Looking for a flavor-packed, seasonal breakfast or brunch treat that brings together the bold tang of rhubarb and the rich warmth of brown butter crumble? This Rhubarb Coffee Cake with Brown Butter Crumble is exactly what you need. With a soft, cake-like base, vibrant rhubarb swirl, and crunchy topping infused with nutty caramelized butter, this baked coffee cake delivers all the comforting flavors of spring in one irresistible slice.
Perfect for weekend baking , holiday breakfasts , or when you’re craving something sweet but not overly sugary, this easy-to-make coffee cake uses simple ingredients like flour, butter, and fresh rhubarb to bring bold flavor into your kitchen. Whether you’re following a low-carb lifestyle , doing gluten-free baking , or simply love the bright tartness of rhubarb, this coffee cake will quickly become a favorite in your home rotation.
In this article, we’ll walk you through how to make this perfect rhubarb coffee cake from scratch , explore ingredient substitutions, offer serving ideas, and answer your most common questions. Let’s get started!
Why You’ll Love This Rhubarb Coffee Cake
This isn’t just any old coffee cake—it’s a tart, crunchy, melt-in-your-mouth delight made with real ingredients that bring bold flavor and satisfying texture together beautifully.
Here’s why it stands out:
- 🥦 Fresh rhubarb filling : Bright, tart, and perfect for balancing sweetness.
- 🧈 Brown butter crumble topping : Adds depth, richness, and a caramel-like crunch.
- 🍰 Soft, cakey texture : Light and fluffy without being heavy or dense.
- 🍯 Naturally sweetened option available : Can be made keto-friendly with erythritol.
- ⏱️ Ready in under an hour
- 🧁 Great for gifting or sharing
- 🧼 Easy cleanup : One bowl and a pan—no mixer needed!
Whether you’re making it for yourself, your family, or guests at a brunch, this rhubarb coffee cake with brown butter crumble will quickly become a go-to comfort dish.
Ingredients You’ll Need
For the Coffee Cake Base:
- 2 cups all-purpose flour (or almond flour for low-carb/keto version)
- 1 tsp baking powder
- 1/2 tsp baking soda
- 1/2 tsp salt
- 1/2 cup unsalted butter, softened
- 3/4 cup granulated sugar or powdered erythritol (for keto)
- 2 large eggs
- 1 tsp vanilla extract
- 1/2 cup plain Greek yogurt or sour cream
- 1 tbsp lemon juice (to enhance rhubarb flavor)
For the Rhubarb Layer:
- 2 cups chopped fresh rhubarb
- 1/4 cup sugar or erythritol
- 1 tsp cinnamon (optional)
- 1 tbsp water (to help rhubarb release juices)
For the Brown Butter Crumble Topping:
- 1/4 cup unsalted butter
- 1/4 cup packed brown sugar or Lakanto Golden sweetener
- 1/2 cup all-purpose flour or almond flour
- 1 tsp ground cinnamon
- Pinch of salt
Optional: Crushed pecans or walnuts for extra crunch
Step-by-Step Instructions
Step 1: Preheat the Oven
Preheat your oven to 350°F (175°C) . Grease a 9×9-inch baking pan or line with parchment paper for easy removal.
Step 2: Make the Brown Butter Crumble
In a small saucepan, melt the butter over medium heat until golden brown and fragrant (about 3–4 minutes). Remove from heat.
In a separate bowl, mix brown sugar (or sweetener), flour, cinnamon, and salt. Add the browned butter and stir until coarse crumbs form.
Set aside for later use.
Step 3: Prepare the Rhubarb Filling
Toss the chopped rhubarb with sugar or sweetener and a splash of water.
Let sit for 10–15 minutes to macerate slightly before using.
Tip: Cook briefly on the stovetop for a compote-style layer.
Step 4: Mix the Dry Ingredients
In a mixing bowl, whisk together:
- Flour (or almond flour for keto version)
- Baking powder
- Baking soda
- Salt
Mix well to evenly distribute.
Step 5: Combine Wet Ingredients
To the dry mixture, add:
- Softened butter
- Sugar or sweetener
- Eggs
- Vanilla extract
- Greek yogurt or sour cream
- Lemon juice
Beat or stir until smooth and thick—but still scoopable.
Step 6: Assemble the Coffee Cake
Pour half of the batter into the prepared pan and spread evenly.
Sprinkle the rhubarb filling over the top.
Drop spoonfuls of the remaining batter over the rhubarb layer and gently spread.
Top generously with the brown butter crumble, pressing lightly to adhere.
Step 7: Bake Until Golden
Bake for 35–40 minutes , or until a toothpick inserted in the center comes out clean.
Let cool completely before slicing for best results.
Step 8: Serve and Enjoy!
Slice into squares or bars and enjoy warm or at room temperature.
Pair with a cup of coffee, tea, or milk for the ultimate breakfast or snack.
Enjoy every soft, gooey bite of your Rhubarb Coffee Cake with Brown Butter Crumble !
Nutritional Information (Per Serving – Makes 12 Servings)
| Nutrient | Amount |
|---|---|
| Calories | ~250 kcal |
| Total Fat | ~12 g |
| Saturated Fat | ~6 g |
| Cholesterol | ~50 mg |
| Sodium | ~200 mg |
| Total Carbs | ~30 g |
| Dietary Fiber | ~1 g |
| Net Carbs | ~29 g |
| Protein | ~4 g |
Note: Values may vary based on exact measurements and optional add-ins.
Tips for the Best Rhubarb Coffee Cake
- Use fresh rhubarb – Frozen works too, but fresh gives the best texture.
- Don’t skip browning the butter – It adds incredible depth and richness.
- Layer the rhubarb carefully – Too much moisture can sink into the cake if not balanced.
- Cool before slicing – Keeps the cake from crumbling or sticking.
- Store in a sealed container – Keeps fresh for up to 3 days at room temperature.
Variations & Customizations
Want to switch things up? Try these tasty variations:
Low-Carb/Keto Version
Use almond flour in place of all-purpose flour and replace sugar with erythritol or monk fruit.
Streusel Twist
Add crushed graham crackers or oats to the topping for a classic coffee cake feel.
Chocolate Rhubarb Swirl
Mix cocoa powder into the cake batter or drizzle melted dark chocolate on top.
Vegan Option
Replace butter with coconut oil, eggs with flax eggs, and dairy with plant-based alternatives.
Mini Muffin Cakes
Fill muffin tins halfway with batter, add rhubarb, then more batter and crumble topping.
Frequently Asked Questions (FAQ)
Is this truly keto-friendly?
Yes, with minor adjustments—use almond flour and a low-carb sweetener like erythritol or monk fruit.
Can I use frozen rhubarb?
Yes! Thaw and drain well before using to avoid excess moisture.
How do I store leftover coffee cake?
Store cooled slices in an airtight container at room temperature for up to 3 days , or refrigerate for longer freshness.
What kind of sweetener works best for keto?
Erythritol or monk fruit are ideal for texture and sweetness. Allulose also works well and offers a more traditional mouthfeel.
Can I make this gluten-free?
Yes! Replace all-purpose flour with 1:1 gluten-free flour blend or almond flour for a grain-free version.
Why This Recipe Works So Well
This Rhubarb Coffee Cake with Brown Butter Crumble works because of its perfect balance of textures and bold flavors:
- The rhubarb gives a vibrant, tart contrast to the cake’s natural sweetness.
- The brown butter adds a deep, caramelized richness that enhances every bite.
- And the crumbly streusel topping gives a satisfying crunch that elevates the entire experience.
It’s the kind of dessert that makes eating seasonal produce feel indulgent—because it tastes so good.
Serving Suggestions
Looking for creative ways to serve your coffee cake beyond just a plate? Here are some ideas:
In Mason Jars
Crush a piece and layer with whipped cream and berries for a parfait-style treat.
At a Brunch Spread
Serve with scrambled eggs, bacon, and fresh fruit for a cozy weekend breakfast.
With Coffee or Tea
Pair with espresso, black coffee, or herbal tea for a cozy afternoon snack.
Gift-Worthy Packaging
Wrap individual slices in parchment paper and tie with twine for thoughtful homemade gifts.
In Lunchboxes
Pack with cheese sticks, nuts, or veggies for a balanced keto lunch.
Health Benefits of Key Ingredients
Let’s take a quick look at the health benefits of what makes this dessert special:
Rhubarb
Low in calories and high in fiber and vitamin K—supports digestion and bone health.
Almond Flour (Keto/GF Version)
Rich in vitamin E and healthy fats—great for heart and skin health.
Brown Butter
Contains fat-soluble vitamins A, D, E, and K—important for hormone production and brain function.
Even though this is a coffee cake, it’s packed with nutrients that make it more than just a treat—it’s a smart addition to your balanced lifestyle when enjoyed mindfully.
Final Thoughts: A Must-Try Springtime Breakfast Treat
This Rhubarb Coffee Cake with Brown Butter Crumble proves that going low-carb doesn’t mean missing out on your favorite baked goods. With its soft cake base, zesty rhubarb filling, and crispy streusel finish, it’s the kind of treat that turns a simple cake into something magical.
Whether you’re new to keto, looking for a refreshing morning snack, or want to impress with homemade treats, this coffee cake deserves a spot in your kitchen. It’s easy to make, customizable, and loved by kids and adults alike.
So go ahead—whip up a batch, share it with friends, or savor it solo. Either way, you’re treating yourself to something truly special.
Print
Rhubarb Coffee Cake with Brown Butter Crumble – Sweet, Tart & Perfectly Baked!
- Total Time: 60 mins
Description
This delightful cake combines tangy rhubarb and rich brown butter crumble.
Ingredients
2 cups rhubarb, chopped ½ cup sugar 1 teaspoon vanilla 4 tablespoons butter, softened ½ cup sugar 1 cup flour ½ teaspoon baking powder ½ teaspoon baking soda ¼ teaspoon salt 1 egg 1 teaspoon vanilla extract ¾ cup Greek yogurt 4 tablespoons butter ¼ cup sugar ½ cup flour ¼ teaspoon salt
Instructions
Preheat the oven to 350º. Line an 8 x 8 inch baking pan with parchment paper and butter the sides.
Filling: Add ½ cup of sugar, rhubarb, 1 teaspoon of vanilla, and ¼ cup water to a saucepan. Cook over medium heat until the rhubarb has softened, about 10 minutes. Let it cool completely. Once cooled, drain with a metal sieve to remove excess liquid.
Crumble: Add ½ cup of flour and ¼ cup of sugar to a small bowl. Add the butter to a small saucepan over medium heat and cook until it begins to turn brown. Pour the butter over the flour and sugar mixture and stir with a fork until incorporated. Set aside.
Cake: Cream butter and sugar in a large mixing bowl of an electric mixer until light and fluffy, about 2 minutes. Add the egg and mix until incorporated. Add yogurt and vanilla and mix well. Slowly add the flour and mix just until there is no flour visible. Spread half of the batter in the prepared pan. Place half of the drained rhubarb on the cake batter. Place the rest of the cake batter over the rhubarb. Top with the remaining rhubarb. Sprinkle all of the crumble over the cake and bake for 40-45 minutes until the crumble is golden brown and a toothpick comes out with just a few crumbs.
- Prep Time: 20 mins
- Cook Time: 40 mins
Nutrition
- Serving Size: 12
- Calories: 223
- Fat: 8g
- Carbohydrates: 33g
- Protein: 4g