Prep Time 30 minutes mins
Cook Time 35 minutes mins
Resting Time 2 hours hrs
Total Time 3 hours hrs 5 minutes mins
Brown the butter until the milk solids turn deep golden and smell nutty, then rapidly transfer to a cool bowl to halt cooking and avoid bitterness. Ensure all dairy is at room temperature so the batter emulsifies and the frosting stays silky without splitting. Natural cocoa gives that classic red hue, but if using Dutch-process reduce food coloring slightly and add 1/4 teaspoon extra vinegar to keep the color vibrant. If your browned butter solidifies too much before making frosting, let it sit at room temp until soft-spreadable; cold chunks will make lumpy icing. Avoid overmixing once flour is added to keep the crumb tender, and weigh pans to divide batter evenly for even layers. The cake keeps refrigerated, covered, for up to 4 days; bring to room temperature before serving for best texture.