Strawberry Rhubarb Brown Butter Cake

This strawberry rhubarb layer cake is one of my favorite cake recipes. The combination of brown butter cake layers with tart strawberry rhubarb compote and lightly sweetened mascarpone is perfectly balanced. I love slicing into it to reveal the gorgeous interior, with four layers of tender cake offset by the bright fruit compote.

Although this cake looks impressive, it’s surprisingly simple to make. The cake layers come together in just a few minutes, and there’s no fussy steps like whipping egg whites separately. The strawberry rhubarb filling only requires three ingredients and a quick cook on the stove, and the mascarpone whipped cream is as simple as it gets! 

This is the perfect cake for spring and early summer gatherings, highlighting the first fruit of the year between those lovely layers.

Recipe highlights

• Tart rhubarb + juicy strawberries + brown butter cake + creamy mascarpone
• Soft, tender white cake with a no-fuss technique
• Gorgeous presentation with colorful layers
• The perfect balance of tart and sweet
• Surprisingly simple to make

How to make this strawberry rhubarb cake

Find the full ingredients list and detailed recipe instructions in the recipe card at the bottom of this post. Here’s a quick step-by-step overview of how to make this recipe:

1. Make the brown butter: Melt butter on medium-low until golden brown, then pour into a bowl and let cool to solid room temperature.
2. Make the strawberry rhubarb cake filling: Place fruit in a pot with the sugar and cook until fully broken down and quite thick, stirring often, about 10-15 minutes. Cool.
3. Combine wet ingredients for cake: Whisk together egg whites, vanilla, and milk.
4. Make the cake batter: In a stand mixer, combine dry ingredients, then add soft brown butter, blending until mixture looks like breadcrumbs. Add all but ¼ cup of milk mixture and beat on medium speed until thick and creamy. With the mixer on low, gradually pour in remaining milk.
5. Bake: Divide batter between 2 buttered, lined pans and bake until golden brown.
6. Make the mascarpone whip: Whisk mascarpone, cream, sugar, and vanilla to soft peaks.
7. Layer the cake: Slice each cake in half horizontally to make 4 layers. Spread the first layer with compote, then the next with whipped mascarpone. Spread more compote on the third layer, then top with the final cake layer.
8. Frost: Ice the cake with mascarpone whipped cream and decorate as desired.

Making the brown butter

The key to making brown butter is letting it cook just long enough before it starts to burn. Follow these steps:

• Slice the butter into a few pieces and melt it in a saucepan over medium-low heat. 
• Continue to cook the butter, watching it carefully. It will sputter and spurt at first, then it will start to quiet down.
• Cook until the bubbles start to subside and the bottom of the liquid begins browning.
• Once the butter takes on a golden brown color, remove it from heat. It should smell nutty and have little brown bits in it. 
• Pour it in a small bowl and let it cool back to room temperature. It should be soft and spreadable when you use it to make the cake batter.

Variations & substitutions

Brown butter: Don’t feel like browning the butter? Skip this step and use regular unsalted butter at soft room temperature.

Cake filling: Try swapping the strawberries for raspberries for a slight flavor variation.

Add citrus zest: A little fresh lemon or orange zest added to the strawberry rhubarb cake filling brings a little extra flavor boost.

Mascarpone whipped cream: Want a different frosting? Try crème fraîche whipped cream, vanilla buttercream, brown sugar buttercream, or even lilac buttercream.

Storage

Store this strawberry rhubarb cake in the refrigerator, wrapped tightly, for up to 4 days. The cake is delicious served chilled or at room temperature.