The Silver Palate’s Chocolate Cake

Step 1

Preheat the oven to 350 degrees. Butter and flour a 10-inch tube pan.

Step 2

Cut the chocolate and butter into small pieces and place in a large bowl. Pour 1 cup boiling water over them; let stand until melted. Stir in the vanilla and sugar, then whisk in the egg yolks, one at a time.

Step 3

In a small bowl, mix the baking soda and sour cream and whisk into the chocolate mixture. Sift the flour and baking powder and add to the batter, mixing thoroughly.

Step 4

Beat the egg whites until stiff but not too dry. Stir a quarter of the egg whites thoroughly into the batter. Gently fold in the remaining whites.

Step 5

Pour the batter into the prepared pan. Set on the center rack of the oven and bake until a cake tester inserted into the center comes out clean, 40 to 50 minutes. Cool in the pan for 10 minutes, unmold and cool completely before frosting.

Step 6

To make the frosting: Place all the ingredients in a heavy saucepan over low heat and whisk until smooth. Spread on the cake while the frosting is still warm.