Okay, chocolate and blueberries might not be the first combination that pops into your head when you’re standing in the kitchen thinking about cake. Chocolate and strawberries? Sure. Chocolate and raspberries? Been there. But blueberries?
Stay with me, because this one gets very good, very quickly.
This Chocolate Blueberry Cake combines rich chocolate layers with sweet-tart blueberry filling and fluffy blueberry buttercream. And despite looking like the sort of cake that requires a pastry degree and an entire Saturday sacrificed to the baking gods, the chocolate cake itself is surprisingly uncomplicated.
You don’t even need a mixer for the cake batter. Bless it.
The cake uses vegetable oil instead of softened butter, which keeps things simple and helps produce moist layers. You’ll need granulated sugar, all-purpose flour, unsweetened Dutch-process cocoa powder, baking powder, baking soda, salt, vegetable oil, eggs, vanilla extract, full-fat buttermilk, and hot coffee.
Yes, coffee.
No, we’re not suddenly making a mocha cake. The hot coffee helps deepen the chocolate flavor, and frankly, chocolate can use all the encouragement we’re willing to give it.
Make sure your eggs and buttermilk are at room temperature before getting started. If you forgot to take the eggs out of the refrigerator because you are a normal human being who does not organize her day around cake ingredients, put them in a bowl of lukewarm water for about 15 minutes.
Start by whisking the flour, sugar, cocoa powder, baking powder, baking soda, and salt together in a large bowl. Stir in the vegetable oil, followed by the eggs and buttermilk, mixing well after each addition. Finally, gently stir in the hot coffee until everything is just combined.
Divide the batter evenly between two parchment-lined 8-inch round cake pans and bake according to your cake recipe until the layers are done. Let them cool completely before attempting the frosting situation. Warm cake and buttercream are not friends, and nobody needs to learn that lesson while holding a spatula.
While the cakes cool, prepare your blueberry filling and allow that to cool completely too.
And this is where the recipe gets clever.
That blueberry filling isn’t just going between the chocolate layers. Some of it goes directly into the buttercream, so you get blueberry flavor throughout the whole cake without making two completely separate berry concoctions.
For the frosting, beat unsalted butter and powdered sugar until light and fluffy. Add heavy cream, vanilla extract, a pinch of salt, and some of the cooled blueberry filling. Keep mixing until you’ve got a smooth, fluffy blueberry buttercream with that gorgeous natural berry color.
Then comes assembly.
Place your first chocolate layer down and pipe a ring of blueberry buttercream around its outer edge. This little frosting wall is important because you’re about to spoon blueberry filling into the middle, and we would ideally like it to remain inside the cake instead of making a dramatic escape down the sides.
Add the second cake layer and finish frosting the outside with the blueberry buttercream. Fresh blueberries on top make an easy finishing touch without requiring you to suddenly develop professional cake-decorating skills.
You can also turn this into a mixed berry chocolate cake by swapping the blueberries for a frozen triple-berry blend and preparing the filling the same way.
Once assembled, keep the cake covered in the refrigerator for up to four days. Bring it back toward room temperature before serving so the cake and buttercream have a softer texture. It can also be wrapped well and frozen in an airtight container for up to two months.
And there you have it: dark chocolate cake, bright blueberry filling, creamy berry frosting, and fresh blueberries piled on top.
It’s a little unexpected, very pretty, and considerably easier than it looks.
Which, quite frankly, is exactly how I prefer my cakes.
