Blueberry Chocolate Cake

This Blueberry Chocolate Cake is a decadent dark chocolate cake topped with blueberry buttercream! This one-layer cake is simple, delicious, and you can't beat the color of that blueberry frosting!

Course Dessert

Cuisine Cakes

Prep Time 30

Cook Time 42

Chill Time 20

Servings slices

Calories 670kcal

Author Amee

Ingredients

Dark Chocolate Cake

3 oz bittersweet chocolate, finely chopped (I used 60% cacao)
⅓ cup dark (dutch process) unsweetened cocoa powder (see note)
¾ cups freshly brewed coffee, hot (see note)
¾ cups flour (I used all-purpose flour)
¾ cups sugar
½ teaspoon baking soda
¼ teaspoon salt
6 Tablespoons vegetable oil
2 eggs, at room temperature (I used large eggs)
2 teaspoon white vinegar (see note)
1 teaspoon vanilla extract
1 teaspoon chocolate extract (see note)

Blueberry Buttercream

1 ½ cups blueberries, fresh or frozen (about 9 oz.)
1 tablespoon sugar
1 tablespoon lemon juice
1 cup unsalted butter, at room temperature
4 cups powdered sugar, sifted

US Customary - Metric

Instructions

For Cake

Preheat oven to 350° F. Grease an 8" cake pan and set aside.
In a medium heatproof bowl, combine chopped chocolate and cocoa powder. Pour hot coffee (see note) over the top and whisk until smooth. Refrigerate chocolate mixture for 10 minutes (so the mixture doesn't cook your eggs).
While the chocolate mixture is chilling, combine the flour, sugar, salt, and baking soda in a large bowl. Set aside.
After chilling (mixture will still be warm, but not hot), remove chocolate mixture from the refrigerator. Add oil, eggs, vinegar (see note), vanilla extract, and chocolate extract (see note), whisking until smooth.
Pour chocolate mixture into flour mixture and whisk until smooth. Pour the batter into the prepared pan.
Bake 30-34 minutes, or until a toothpick inserted in the center comes out clean, or with a few moist crumbs attached. I turn the pan around in the oven halfway through baking to help ensure an even bake.
Cool cake 10 minutes in the pan, then turn out onto a wire rack to cool completely.

For Buttercream

Combine blueberries, sugar, and lemon juice in a saucepan. Cook over medium-low heat, stirring occasionally, until the blueberries break down and give off their juice, about 5 minutes.
Strain the blueberries through a fine mesh strainer, discarding the skins/seeds. Pour the blueberry juice back into the saucepan and simmer over medium-low heat until reduced by half, about 5-10 minutes. (I started off with 1 cup of blueberry juice, and reduced it to ½ cup). Make sure to stir it often as it cooks so that it doesn't stick to the pan or scorch as it thickens. Allow the blueberry reduction to cool to room temperature.
Cream butter and powdered sugar in the bowl of a stand mixer until smooth. Gradually add the blueberry reduction (should be about ½ cup) and mix to incorporate.
Once the cake is completely cool, frost with the buttercream and decorate as desired.
You can store your Blueberry Chocolate Cake covered on your counter for up to two days, or covered in your refrigerator for up to five days.
Enjoy!

Notes

Note on chocolate: I used dark (60% cacao) chocolate in both the cake and the ganache. You can use whatever kind of chocolate you prefer, but I highly recommend a dark chocolate, as it is rich and decadent without being too sweet!

Note on dark (dutch process) cocoa: *Not* the same as natural cocoa powder, dark (or dutch process) powder is darker and smoother.

Note on coffee: The cake won't taste like coffee, I swear! The coffee enhances the chocolate flavor, and I highly recommend it! If you would prefer not to use coffee, you can use hot water instead.

Note on vinegar: This may seem like a strange ingredient in a cake, but SCIENCE! The vinegar reacts with the baking soda (think second grade volcano science project), which gives your cake a lighter, fluffier texture. You won't taste the vinegar. That said, if you don't have white vinegar, consider taste in what you substitute. Apple cider vinegar would be a good fit, but your aged balsamic would lend a strange flavor.

Note on chocolate extract: I highly recommend this (sometimes overlooked) extract! It lends an amazing depth of flavor to chocolate baked goods! You can even make yourself some Homemade Chocolate Extract for next time!

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