| |
|
butter, for coating cake pans
|
|
2 cups sugar
|
|
1 3/4 cups cake flour
|
|
2 tablespoons cornstarch
|
|
1 teaspoon baking soda
|
|
3/4 teaspoon salt
|
|
2/3 cup unsweetened cocoa, preferably Dutch process
|
|
1 teaspoon instant coffee
|
|
3/4 cup boiling water
|
|
1/2 cup sour cream
|
|
1 teaspoon vanilla extract
|
|
4 large egg whites, at room temperature (you may want to save yolks to use in the frosting)
|
|
14 tablespoons (1 3/4 sticks) unsalted butter, melted, but not hot
|