Heat oven to 350 degrees F. Sift together the cake flour, baking powder, and salt and set aside. Using the butter wrapper, butter an 8 1/2 by 4 1/2 by 2 1/2-inch glass loaf pan; set aside.
In a bowl of an electric mixer, fitted with the paddle attachment, cream the butter and sugar in a large bowl until light and fluffy, about 5 minutes. Add the eggs 1 at a time, mixing to incorporate after each one. Stir in vanilla and almond extract.
Add the dry ingredients, alternating with the buttermilk, starting and ending with the flour. Set aside 1/3 of the batter.
In small bowl using a rubber spatula, combine cocoa powder and 6 tablespoons boiling water together. Mix until smooth. Add mixture to reserved 1/3 of batter. Stir until well combined.
Fill the prepared pan by alternating large spoonfuls of the vanilla and chocolate batters, simulating a checkerboard pattern. Run a wooden skewer or paring knife through batter in a circular motion. Bake until a cake tester comes out clean, 40 to 50 minutes. Remove to a wire rack to cool, invert after 5 minutes. Cool for about 30 minutes. Spoon glaze on slightly cooled cake, letting it drip down the sides. Let the glaze dry for about 1/2 of an hour, slice and serve. Store airtight container up to 4 days.
In a small bowl using a wooden spoon combine the butter, confectioners' sugar, and milk. Stir until smooth and pourable.
Yield: 1/3 cup
(c)2003 Martha Stewart Living Omnimedia, Inc. All Rights Reserved.