Ingredients
- All-purpose flour — all-purpose flour gives you a moist crumb while also giving the chocolate cake structure.
- Cocoa powder — as there is plenty of sugar in this cake recipe, be sure to use unsweetened cocoa powder. You need cocoa powder for the cake batter and the creamy buttercream frosting.
- Leavening agents — yes, you need both to help the cake rise well. Check the expiration date on these items before using them. They become less effective as time goes on.
- Milk — I recommend using whole milk for a rich, moist chocolate cake and extra creamy buttercream.
- Eggs — bring the eggs to room temperature before using them. Simply set them out 30 minutes to an hour before you intend to start baking.
- Vegetable oil — A vegetable oil, like canola oil, adds moisture to the cake.
- Boiling water — the water must be hot! Hot water helps to bring out more of that incredible chocolate flavor, as well as adding to the moisture of the cake. Or, use hot brewed coffee instead (more on that below).
Step-by-Step Instructions
1. Sift the dry ingredients (flour, granulated sugar, cocoa, baking soda, baking powder, and salt) into a large bowl. Whisk to combine.
2. In a smaller bowl, whisk together the wet ingredients (milk, egg, oil, and vanilla). Add the wet ingredients to the bowl with the dry ingredients and whisk it all until well incorporated.
3. Pour in the boiling water and whisk again. You will end up with a runny cake batter. (It will be runnier than you expect, but don’t be tempted to add more flour.)
4. Grease 2 round 9-inch cake pans and line the bottom of each with parchment paper to make removing the chocolate cake easier. If you have them, use cake strips to help the cakes bake more evenly. Once the cake pans are prepared, divide the cake batter evenly between them. Bake the cakes for 35 minutes at 350°F or until a toothpick inserted in the center of the cake comes out clean. Keep the cakes in the baking pans on a wire cooling rack for 15 minutes. Then carefully invert them onto the wire racks. Let them cool completely.
5. While the cakes are cooling, you can prepare the decadent chocolate buttercream frosting. You’ll need a stand mixer fitted with the paddle attachment for this part. In the bowl of the stand mixer, beat the butter on medium speed for about 2 minutes. Add the cocoa powder and salt and mix on low to incorporate them. Scrape the bowl.
6. Keep the speed on low and add a little powdered sugar at a time, alternating with small amounts of milk (up to 4 tablespoons total of whole milk). Once you’ve added all the sugar, add the vanilla extract and beat on medium-low speed for approximately 1 minute, until you have a fluffy buttercream.
7. Once the cakes have cooled completely, it’s time to assemble your chocolate cake! Place one layer on a cake stand and top it with 1 cup of frosting. Spread the frosting right to the edges before carefully placing the other cake layer on top.
8. Spread the rest of the frosting on top and around the sides of the cake. If you’re feeling fancy, you can save some of the buttercream frosting to pipe decorations.