Keto Rhubarb Oatmeal Bars That Don’t Taste Like Diet Food

I didn’t grow up eating rhubarb. Honestly, I thought it was some weird celery cousin until my neighbor dropped off a brown bag full of bright pink stalks one summer. “Make something with these,” she said. Challenge accepted.

The first thing I ever baked? A batch of rhubarb oatmeal bars that didn’t look like much but were gone in an hour. Ever since, rhubarb’s had a permanent spot in my freezer. And let me tell you—these keto rhubarb oatmeal bars are something else. Sweet, tart, crumbly, buttery… and not a trace of white sugar.

Whether you’re cutting carbs, can’t stop eating rhubarb desserts recipes, or just looking for something to snack on that won’t spike your blood sugar into next week—this one’s for you.

What You’ll Need

Before we get into the full recipe, here’s what makes these bars hit that sweet spot without messing up your diet:

The Base:

• Almond flour – replaces regular flour, keeps carbs low

• Coconut flour – helps with texture, gives a slight chew

• Unsweetened shredded coconut – for body and flavor

• Butter – don’t skimp here

• Sugar substitute – like erythritol, monk fruit, or allulose

• A pinch of salt

The Filling:

• Fresh or frozen rhubarb – chopped

• Raspberries (optional) – for that raspberry rhubarb crumble bars flavor

• Lemon juice – for tang

• Xanthan gum or chia seeds – helps thicken the filling

• Sugar substitute again – no need for the real stuff

The Crumble Topping:

Basically, you’ll reserve some of the base and sprinkle it on top.

Step-by-Step: Making Rhubarb Oatmeal Bars (Keto Style)

1. Preheat your oven to 350°F (175°C).

Line an 8×8 or 9×9 baking pan with parchment paper. Grease it too—trust me, cleanup will be easier.

2. Make the crust and topping.

In a large bowl, mix together:

• 2 cups almond flour

• 1/2 cup coconut flour

• 1/2 cup unsweetened shredded coconut

• 1/2 tsp salt

• 1/2 cup melted butter

• 1/3 to 1/2 cup sugar substitute (taste it)

Press 2/3 of this mix into your baking pan. Save the rest for the crumble topping.

Bake this bottom layer for 10 minutes until it’s just starting to set. Pull it out and let it cool.

3. Cook the filling.

In a saucepan, toss in:

• 2 cups chopped rhubarb

• 1/2 cup raspberries (optional, but amazing)

• 2 tbsp lemon juice

• 1/2 cup sugar substitute

• A pinch of xanthan gum or 2 tsp chia seeds

Let it simmer until the rhubarb starts to break down and the mix thickens up. Stir often. Don’t let it burn.

4. Build your bars.

Spread the fruit filling over the cooled crust. Crumble the remaining oat-almond topping all over.

5. Bake again.

Slide the pan back into the oven for 20-25 minutes, or until the top starts to turn golden. Cool completely before cutting—otherwise you’ll end up with rhubarb mush.

Why These Bars Work (And Taste Like a Cheat Meal)

Most low-carb desserts taste… off. Like someone tried to make a sugar cookie using toothpaste and regret. But not these. These keto rhubarb oatmeal bars have layers. The base is soft and buttery, almost like shortbread. The filling is jammy but tart enough to keep it interesting. And the topping? Crispy, toasty, coconutty goodness.

They remind me a little of the rhubarb dream bars Taste of Home used to print—except without the sugar crash. Honestly, they might beat out those rhubarb custard bars Taste of Home fans swear by. Bold, I know.

What Makes These Keto?

Let’s break it down. A traditional batch of rhubarb dessert bars can hit you with 30+ grams of carbs per slice. These guys? More like 3–4 net carbs. That’s because we skip the flour, oats, and sugar.

Now, yes—we’re calling them rhubarb oatmeal bars. And technically there’s no “real” oatmeal in here. But that shredded coconut gives that chewy oat vibe, and your brain won’t even question it. You could toss in a few tablespoons of chopped nuts too if you want a heartier bite, kind of like rhubarb oat bars your grandma used to make.

Can I Eat These keto Rhubarb Oatmeal Bars for Breakfast?

You mean like rhubarb breakfast bars? Absolutely. They’re not too sweet, they’re full of fiber, and they go great with coffee. You could even drizzle a little heavy cream on top if you’re feeling fancy.

In fact, I made a batch last week and ate one straight from the fridge with some Greek yogurt. Felt like dessert. Looked like breakfast. Win-win.

Flavor Twists (No Sugar, Still Delicious)

Got a freezer full of random fruit? Swap out or mix with rhubarb:

• Strawberries – Like rhubarb strawberry cobbler Taste of Home vibes

• Blueberries – Sweetens things up naturally

• Blackberries – For a deeper flavor hit

• Lemon zest – If you like rhubarb and lemon recipes, this one’s gold

You could even sprinkle a few chopped walnuts or pecans in the crust to copy that Amish rhubarb bars feel.

Storage Tips

Don’t leave these out overnight unless you like soggy bottoms. Once they’ve cooled:

• Store in an airtight container in the fridge for up to a week

• Freeze in layers with parchment in between—great for prepping ahead

They’re solid cold but can be gently warmed in a toaster oven or microwave if you want that fresh-baked taste.

More Rhubarb Desserts Worth Trying (Especially if You’re Keto Curious)

If this recipe got you hooked, there’s a whole secret world of rhubarb desserts recipes out there. Some favorites:

• Keto oatmeal rhubarb cookies – Like soft granola bars, but keto

• Keto rhubarb custard bars – Rich, tangy, kind of like cheesecake

• Mini rhubarb crisps – Skip the oats, use almond meal and nuts

• No-bake rhubarb dream bars Taste of Home fans love – Use gelatin and cream cheese

And if you’re still craving that real crumble texture, try mixing a tablespoon or two of psyllium husk or chopped nuts into your topping. You’ll get that rustic, rhubarb oat bars finish without the carbs.

Conclusion

I bake these rhubarb oatmeal bars more than I care to admit. My sister once brought them to her book club, and someone asked if they were from a bakery. Joke’s on them—she can barely boil pasta. But they really are that good.

If you’re someone who misses those Taste of Home strawberry rhubarb crisp days or wishes you could still eat those rhubarb bars recipes from church potlucks… try this. You don’t have to give up flavor just because you’re watching carbs. And once you make them, don’t be surprised if they don’t last past the weekend.

Print the recipe. Freeze a batch. Tell nobody. Or share, whatever. Just don’t forget the parchment paper, unless you like chiseling dessert out of a baking dish.

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