Ingredients:
Butter - 1/2 cup (1 stick)
Cake flour - 1 3/4 cups
Baking powder - 2 tsp
Salt - 1/2 tsp
Sugar - 1 cup
Eggs - 3
Vanilla extract - 1 tsp
Buttermilk - 2/3 cup
Dutch-process cocoa powder - 3 tbsp
1. Preheat oven to 350F. Butter a 9 by 5 inch loaf pan.
2. Sift together the cake flour, baking powder and salt and keep aside.
3. Beat the butter and sugar until light and fluffy.
4. Add the eggs one at a time, beating until combined after each addition.
5. Mix in the vanilla.
6. Add the flour mixture alternating with the buttermilk. Start and finish with the flour mixture. Set aside 1/3 of the batter.
7. In a bowl, mix cocoa and 3 tbsp of boiling water. Mix well and add to the reserved batter.
8. Spoon in the batter into the prepared tin in 2 layers. Each layer should have a checkered board pattern by alternating spoonfuls of vanilla and chocolate batter.
9. For the marbling effect, run a skewer or a knife through the batters in a swirling motion.
10. Bake for 40 - 50 minutes.