If you want a show-stopper dessert for Halloween that still fits your low carb life, these keto black velvet cupcakes with cocoa buttercream are it.

They look dark and dramatic, taste like a rich chocolate cupcake with a soft crumb, and the frosting whips up thick and silky. No fancy chef moves.

No hard-to-find stuff. Just a little black cocoa magic, a good mixer, and a plan.

I’ve baked enough keto cupcakes to learn where they often go wrong: dry crumb, eggy aftertaste, frosting that tastes like sweetener.

We’re dodging all that here. The batter uses a smart mix of almond flour and a touch of coconut flour for structure.

We bloom the cocoa so the chocolate flavor pops. We add a tiny hit of vinegar for that classic velvet tenderness. And we balance two sweeteners so the sweetness tastes clean, not icy or cooling.

Grab your spooky sprinkles (sugar-free) if you have them. Or keep them stark and sleek. Either way, they look like they belong on a haunted dessert table.

What makes these “black velvet” and still keto?

Traditional “black velvet” bakes lean on black cocoa powder for color and a mellow, Oreo-style chocolate vibe. Black cocoa is just cocoa that’s heavily Dutched. It’s low in acidity, very smooth, and jet black. Use it alone and the flavor can taste a little one-note; mix it with a bit of regular Dutch-process cocoa and boom—color plus depth.

To keep carbs low, the flour base is almond flour with a spoon of coconut flour for lift. The sweetener combo is powdered erythritol–monk fruit (for structure) with a little allulose (for moisture). No wheat, no sugar, still real cake texture.

And the frosting? Classic buttercream method, but keto. We use butter, cocoa, powdered sweetener, a splash of heavy cream, and vanilla. The frosting pipes like a dream and actually tastes like chocolate, not sweetener.

Ingredient Notes (simple and straight)

For 12 cupcakes

Dry ingredients

1 ¼ cups (125 g) fine almond flour (blanched, super-fine; not almond meal)
2 tbsp (14 g) coconut flour
¼ cup (20 g) black cocoa powder
2 tbsp (12 g) Dutch-process cocoa powder (regular Dutched, not natural cocoa)
1 ½ tsp baking powder
¼ tsp baking soda
¼ tsp xanthan gum (helps bind; optional but nice)
¼ tsp fine sea salt

Wet ingredients

3 large eggs, room temp
½ cup (120 ml) unsweetened almond milk, room temp
½ cup (113 g) unsalted butter, melted and cooled to lukewarm
¼ cup (60 ml) avocado oil (or light olive oil)
½ cup (100 g) granulated erythritol–monk fruit blend
2 tbsp (24 g) allulose (or powdered allulose)
1 ½ tsp vanilla extract
1 tsp apple cider vinegar (or white vinegar)

Color boost (optional but helps)

¼–½ tsp black gel food color (keto-safe brand). You can skip it; black cocoa already gives a deep shade, but gel color makes it black-black.

Note on activated charcoal: it can affect certain meds. Skip it here. Black cocoa + a touch of gel color does the job.

Cocoa Buttercream (Keto)

¾ cup (170 g) unsalted butter, very soft but not greasy
¾ cup (75 g) powdered erythritol–monk fruit (powdered is key so it dissolves)
2 tbsp (12 g) Dutch-process cocoa powder
1 tbsp (6 g) black cocoa powder (for color + a hint of that Oreo vibe)
2–4 tbsp heavy cream (start with 2; add more as needed)
1 tsp vanilla extract
Pinch fine sea salt
Optional: 1 tbsp (12 g) allulose, powdered, if you want even silkier texture

Tools that help

12-cup muffin tin + paper liners (black liners look great)
Mixing bowls
Whisk + spatula
Hand mixer or stand mixer with paddle/whisk
Fine mesh sieve
Ice cream scoop for even batter portions
Piping bag + large star tip (or just spread frosting with a knife)

Step-by-step: the cupcake base

Preheat and prep
Heat oven to 350°F (175°C). Line a 12-cup muffin pan. If your oven runs hot, drop temp to 340°F (171°C) after 10 minutes.
Bloom the cocoa
In a small bowl, whisk the black cocoa and Dutch cocoa with 2 tbsp hot water until smooth and thick like a paste. This wakes up the cocoa flavor. Let it sit while you do the dry mix.
Dry mix
In a large bowl, whisk almond flour, coconut flour, baking powder, baking soda, xanthan gum, and salt. Break up clumps so the batter stays smooth.
Sweeten the wet mix
In another bowl, whisk melted butter, avocado oil, granulated erythritol–monk fruit, and allulose until it looks glossy. Add eggs one at a time, whisking just to combine. Add vanilla and almond milk.
Add cocoa + color
Whisk the cocoa paste into the wet mix until even. If you’re using black gel color, add a tiny bit now. You can always add a touch more.
Combine
Tip the dry mix into the wet. Sprinkle vinegar on top (the fizz helps tenderness). Whisk until just combined. Don’t over-mix; almond flour batter should look thick but scoopable, not runny.
Portion
Divide batter between the 12 liners (a leveled ice cream scoop per cup works). Smooth the tops a little with the back of a spoon if needed.
Bake
Bake 17–21 minutes, turning the pan at minute 12 if your oven has hot spots. They’re ready when the tops spring back and a toothpick in the center comes out with just a couple moist crumbs.
Cool
Let cupcakes cool in the pan 10 minutes, then move to a rack to cool fully. Frost only when they’re at room temp. Warm cake melts buttercream, which looks… not cute.

Cocoa buttercream, the easy way

Butter base
Beat soft butter in a bowl for 1–2 minutes until pale and fluffy. You’re adding air so the frosting feels light.
Add sweetener + cocoa
Sift in powdered erythritol–monk fruit, Dutch cocoa, and black cocoa. Beat on low until it looks like damp sand, then raise speed. Add vanilla and a pinch of salt.
Loosen
Drizzle in 2 tbsp heavy cream and whip for 1–2 minutes. If you want extra sheen and less sweetener “cooling,” add powdered allulose. Add cream 1 tsp at a time until the frosting is spreadable yet holds peaks.
Taste + tweak
Need more chocolate? Add 1 tsp cocoa. Too stiff? More cream. Too soft? Chill 5–10 minutes, then re-whip.
Pipe or spread
Fill a piping bag with a large star tip and swirl high peaks, or go rustic with a spoon and swoops. Sprinkle with sugar-free Halloween sprinkles or shards of 90–100% chocolate.

Flavor profile (what you’ll taste)

Cupcake: mellow Oreo-adjacent chocolate from black cocoa, a little deeper cocoa from the Dutch powder, soft crumb, not eggy, not dry.
Frosting: chocolate-forward, buttery, silky, lightly sweet. The pinch of salt is small but makes the chocolate pop.

Why this texture works (mini science without the headache)

Almond + coconut flour: almond gives moisture and body; coconut flour is thirsty and helps the batter set, so the cupcake doesn’t slump. A little goes far.
Baking powder + baking soda + vinegar: the baking soda reacts with vinegar for a quick lift; baking powder provides steady rise during baking. Teamwork.
Oil + butter: butter for flavor, oil for tenderness even after chilling. Pure butter cakes can firm up too much in the fridge.
Bloomed cocoa: saturates the cocoa, gives bigger chocolate flavor for the same grams.

Make-ahead plan

Cupcakes: Bake 1–2 days ahead. Wrap cooled cupcakes snug in plastic or an airtight box. Keep at room temp up to 24 hours, then chill. Bring to room temp before serving.
Frosting: Make up to 3 days ahead. Refrigerate in a sealed container. Let it soften on the counter 30–60 minutes, then re-whip 30 seconds. If it looks split, 5–10 seconds of gentle microwave heat plus a quick whip brings it back.
Freeze: Unfrosted cupcakes freeze well for up to 2 months. Wrap each, then bag. Thaw, then frost. Frosted cupcakes can freeze too, but keep them upright and let them thaw uncovered in the fridge to avoid condensation.

Troubleshooting (so you don’t panic at 10 pm)

Batter too thick: add 1–2 tbsp almond milk. It should scoop, not pour.
Batter too thin: your almond flour might be coarser. Whisk in 1 tsp coconut flour and rest 5 minutes. It will thicken.
Cupcakes sinking: oven temp low or over-mixed batter. Check your oven with a thermometer next time; use a gentle hand.
Gritty frosting: sweetener wasn’t powdered or butter too cold. Let it warm and whip longer, or add ½–1 tsp hot cream and beat again.
Cooling sensation from sweetener: add a tablespoon of allulose to frosting or a pinch more salt. The salt blunts that “minty” feel.
Not black enough: add ⅛ tsp more gel color or 1 tsp more black cocoa. Go little by little; it darkens as it sits.

Carb counts and nutrition (estimate)

These numbers are approximations based on common brands.

Per cupcake with frosting (1 of 12):

Calories: ~250–280
Fat: ~24–26 g
Protein: ~5–6 g
Total carbs: ~16–18 g
Fiber: ~3–4 g
Sugar alcohols: ~9–10 g
Net carbs: ~3–4 g

Use your labels and calculator if you need exact macros. Different sweeteners and almond flours vary a bit.

Ingredient swaps that still work

Almond flour: if nut-free is needed, this recipe won’t convert 1:1 to coconut flour only. You can try sunflower seed flour by weight (expect a slight green hue with baking soda; add ½ tsp lemon juice to counter).
Dairy-free: swap butter in cupcakes for more avocado oil (total ¾ cup oil) and use a dairy-free block “butter” in frosting with coconut cream in place of heavy cream. Flavor shifts a bit but still tasty.
Sweeteners: you can use all erythritol–monk fruit, but add 1 more tbsp avocado oil to keep moisture. If using mostly allulose in the cake, note they may brown faster; check early.
Milk: any unsweetened nut milk works. Even water works in a pinch, but milk gives a tender crumb.

How to get that bakery look

Even scoops: use a scoop so each cup bakes at the same rate.
Flat tops for stacking frosting: tap the tin on the counter twice before baking to pop big air bubbles.
Tall swirls: hold the piping tip straight up, start from the outer edge, spiral in, then stack a second layer in the center. Pull straight up to finish.
Contrast: black cupcake, lighter brown frosting. If you want midnight-on-midnight drama, add ½ tsp black cocoa to the frosting too.

Timeline for busy days

Night before: scale ingredients, set out butter for frosting, line the pan.
Morning (or afternoon): bake cupcakes (30 minutes start to finish).
Cool: 1 hour at room temp.
Frosting + piping: 15–20 minutes.
Decorate: 5 minutes. Done.

You can spread this over a couple days if life is doing life things.

Serving ideas for Halloween

Set them on a slate or dark board with a few plastic spiders around (not on the frosting, please).
Top each swirl with a small piece of 90% chocolate or a single sugar-free candy eye for a playful look.
Arrange with tiny candles around the tray for glow.
Pair with black coffee or cold almond milk. Works for grown-ups and the kids who keep stealing them.

Storage

Room temp: 1 day in a cool spot, covered.
Fridge: up to 5 days. The buttercream stays firm but not rock hard. Bring to room temp 20–30 minutes before eating for best texture.
Freezer: up to 2 months. Thaw in the fridge, uncovered, so the frosting doesn’t weep.

Step-by-step recap (short, so you can screenshot it)

Heat oven 350°F (175°C), line 12-cup pan.
Bloom cocoas with hot water.
Whisk dry: almond flour, coconut flour, baking powder, soda, xanthan, salt.
Whisk wet: butter, oil, sweeteners, eggs, vanilla, milk.
Stir in cocoa paste + optional gel color.
Combine wet + dry, add vinegar, stir just until mixed.
Portion and bake 17–21 minutes.
Cool fully.
Beat buttercream and pipe.

Small personal notes (what I learned the hard way)

The first time I tried black cocoa in a keto batter, I used only black cocoa. The cake looked amazing but tasted kind of flat. Mixing with a spoon of regular Dutch cocoa fixed it. You get color and flavor.
Powdered sweetener is not a suggestion here; it’s the difference between silky frosting and little sandy bits. If all you have is granulated, blitz it in a blender until powdered.
A touch of vinegar in velvet cakes really does change the crumb. Don’t skip it. I tried one batch without it and the crumb was tighter.
If your cupcakes come out more brown than black, do not panic. The frosting and the overall look still read Halloween. Also, colors deepen as they sit. Next batch, add a bit of gel color.

Add-ons you can try (still low carb)

Spice it: ¼ tsp cinnamon + a teeny pinch cayenne in the batter for a whisper of heat.
Mocha version: add 1 tsp instant espresso powder to the cocoa bloom.
Salted finish: a few flakes of sea salt on the frosting right before serving.
Filling: scoop a tiny core after baking and cool, fill with sugar-free raspberry jam or whipped cream cheese sweetened lightly. Then frost over the top.

Safety and color note

Since Halloween often inspires intense colors, keep in mind: activated charcoal can bind to some medicines. We didn’t use it here. If you want pitch black, stick to black cocoa and a small dab of black gel color. A little goes far. No weird aftertaste if you keep it light.

How to photograph them Socials

Shoot by a window with indirect light.
Use a dark background so the cupcakes stand out.
Stack three cupcakes in a triangle and focus on the front swirl.
Add a few crumbs on the board; it looks “real.”
Take a close-up of the frosting texture and one bite shot showing the crumb.

Clean-up tips no one tells you

Black cocoa dust can stain wood spoons; use stainless or silicone if you care.
Rinse bowls right away. Dried black cocoa is stubborn.
Keep one towel just for hands so you don’t shade your whole kitchen gray.

Conclusion

These cupcakes taste their very best 20–30 minutes after coming out of the fridge. The buttercream softens slightly, the cupcake relaxes, and the cocoa flavor blooms. It’s a small window where they just sing. Plan for that if you can.

Bake them once and you’ll probably get requests again at Thanksgiving, then at birthdays, then… well, they do that. The color hooks people, but it’s the soft crumb and that chocolate buttercream that keeps everyone quiet at the table for a minute. Which is kind of a miracle at any party.

Happy Halloween baking.