Prep Time 25 minutes mins
Cook Time 30 minutes mins
Resting Time 2 hours hrs
Total Time 2 hours hrs 55 minutes mins
For the brightest hue, use gel food coloring and natural cocoa powder; Dutch-process can mute the color and affect rise. Buttermilk and vinegar react with baking soda for tenderness, so keep them in the recipe and at room temperature for best texture. The hot coffee deepens chocolate notes without adding coffee flavor, but hot water can be substituted. To prevent sticking, fully line pan bottoms with parchment and grease the sides well. If your kitchen is warm, chill the frosted cake briefly between coats to set the crumb layer. The cake layers can be baked a day ahead, wrapped tightly, and refrigerated or frozen for cleaner stacking. Adjust frosting sweetness by adding a pinch more salt or a tablespoon of lemon juice to brighten if desired.