An intensely chocolate layer cake with a shot of espresso and swirls of fudgy buttercream! A simple, but decadent cake perfect for birthday celebrations!
Preheat oven to 350°. Spray two 9-inch pans with vegetable spray. Cut two rounds of parchment to fit easily into the bottom of the pans. Line the pans with the parchment paper and spray again with vegetable spray. Set aside.
In a large bowl, combine the flour, sugar, cocoa powder, baking soda, baking powder and salt. Whisk together until well combined.
In a small bowl, or two cup measuring cup, add the buttermilk, canola oil, eggs and vanilla and whisk to combine.
With your mixer on low-medium speed, slowly add the liquids to the dry ingredients until just incorporated. Mix in the coffee, scraping the bottoms and sides to make sure everything is well combined.
Pour the cake batter evenly into the two cake pans and bake in the oven for 30-35 minutes or until a cake tester comes out clean. Remove the pans from the oven and let the cakes cool to room temperature.
While the cakes are cooling, make the frosting. Add the chocolate to a small bowl and microwave in 15-20 second increments, stirring between each, until the chocolate has melted and is glossy and smooth. Set aside.
In a large bowl, beat the butter until light and airy. Beat in the vanilla and powdered sugar until smooth. Add the melted chocolate and the espresso concentrate and beat until well combined.
Remove one of the cakes from the pan and place upside down on a cake platter. Add about 3/4 cup of icing to the center of the cake and use an offset spatula to spread the frosting over the surface of the cake. Top with the second tier (upside down again) and add the remaining frosting to the top of the cake. Spread evenly over the top and sides of the cake. Scatter your favorite sprinkles or other cake decorations if desired.