Instructions
- Preheat oven to 350°F (175°C). Grease a 9×13-inch pan (or a jelly roll pan for a thinner cake).
- In a large bowl, whisk flour, sugar, salt, and baking soda until evenly combined.
- In a saucepan over medium heat, stir together butter, cocoa powder, and Coca-Cola until smooth. Bring just to a gentle boil, then remove from heat.
- Pour the hot cocoa-cola mixture into the dry ingredients and stir until smooth. Add buttermilk, eggs, and vanilla; mix until glossy and fully combined.
- Pour batter into the pan and bake 30–35 minutes, or until a toothpick in the center comes out clean.
- While the cake bakes (or as it comes out), make frosting: in a saucepan, heat butter, cocoa powder, and Coca-Cola until smooth and hot. Remove from heat and whisk in powdered sugar and vanilla until spreadable.
- Immediately pour the hot frosting over the hot cake and spread gently. Let rest 10–15 minutes before slicing.
Notes
- Pour the frosting while both the cake and frosting are hot for the classic fudgy top.
- Serve slightly warm, room temperature, or chilled—each one is delicious in its own way.
