Marble cake has always been my favorite, what's better than a combination of chocolate and vanilla. This recipe is from the book, Baked - New Frontiers in Baking, and what's interesting is that it uses dark chocolate along with cocoa powder. I had to try it and it makes such a difference in the cake. The chocolate flavor was really intense and just irresistible.
6 oz dark chocolate (60-70% cocoa)
1 tsp dark cocoa powder
3 1/2 cups all purpose flour
1 1/2 tsps baking powder
1 1/2 tsps baking soda
1/2 tsp salt
1 cup unsalted butter, soft but cool, cut into 1" pieces
2 1/4 cups sugar
4 large eggs
16 oz sour cream
1 1/2 tsp vanilla extract
Melt the chocolate over a double boiler. When smooth, add the cocoa powder and whisk till well incorporated. Remove from heat and keep aside.
Preheat oven to 350F. Grease and dust a 10" bundt pan or two loaf pans.
Sift the flour, baking powder, baking soda and salt together.
Cream the butter and sugar for 5 mins till smooth and fluffy. Add eggs one at a time beating well after each addition. Scrape down the bowl and mic for 30 secs.
Add the sour cream and vanilla and beat just until incorporated. Add the dry ingredients in three batches, scraping the bowl before each addition and beating only until each addition is fully incorporated. Do not overmix.
Pour one third of the batter into the chocolate mixture and combine gently with a spatula to make a chocolate batter.
Pour half the plain batter into the pan. Scoop the chocolate batter over the plain batter. Pour the remaining plain batter over the chocolate batter. Run a butter knife through the batter to make swirls.
Bake in the center of the pan for about 1hour, rotating the pan halfway through the baking time, or until a knife inserted in the center of the cake comes out clean.
Cool the cake in the pan on a wire rack for 30 minutes. Then invert it onto the wire rack and cool completely.