Ingredients
Method
- Preheat oven to 325°F (165°C) and grease a 9x5-inch loaf pan with parchment lining. Cream the butter and sugar until pale and fluffy, about 3 minutes.
- Beat in eggs one at a time, then vanilla, red food coloring, and vinegar. Stream in buttermilk with mixer on low.
- Whisk flour, cocoa, baking powder, and salt, then fold into the wet batter by hand until no streaks remain.
- Beat cream cheese, remaining sugar, and egg yolk until smooth. Spread half the red batter in the pan, layer the cream cheese mixture, then top with remaining batter.
- Swirl a butter knife through the layers in a few figure-eight strokes to create ribbons. Smooth the top and tap the pan to release air.
- Bake 55 to 65 minutes until a toothpick comes out with moist crumbs. Cool in the pan 15 minutes, then lift out and cool completely before slicing.
Notes
The cream cheese swirl needs time to set, so let the cake cool all the way to room temperature before you slice into it. If you want a deeper red, use gel food coloring instead of liquid and start with ½ teaspoon.
