Preheat oven to 350'F. Grease (or spray with non-stick cooking spray) three 8" or 8 1/2" round cake pans.
In a small, heavy saucepan over lowest heat, melt chocolate, stirring constantly until smooth; be careful not to scorch. Set aside. Sift together flour, cocoa powder, baking powder, baking soda and salt onto a sheet of wax paper. In a large mixer bowl, w Stir in remaining dry ingredients just until well blended and smooth. Divide batter among pans, spreading in edges.
Bake in the middle of the oven for 23-28 minutes, or until tops are almost firm when tapped and a toothpick inserted in the center comes out moist but clean. Transfer pans to racks and let stand until completely cooled. Layers may be wrapped airtight an d Nutritional information (with fluffy chocolate frosting): Each serving contains 342 calories, 10 grams of fat, 2 grams of saturated fat, 25 milligrams of cholesterol, 202 milligrams of sodium. Percentage of calories from fat: 26.
FLUFFY CHOCOLATE FROSTING: Place egg whites in a large mixer bowl. Set the bowl in a large bowl of very hot tap water and let stand for 10 minutes, stirring occasionally. In a small heavy saucepan set over low heat, melt chocolate, stirring constantly, until smooth; be very careful not to scorch. Set aside to cool sligh t Combine the corn syrup, 1/4 cup water and the sugar in a 2-quarter saucepan, stirring until well blended. Bring to a simmer over medium-heat heat. Cover and boil for 2 minutes to allow steam to wash any sugar from pan sides. Uncover and continue simmeri n With mixer set on medium speed, beat egg whites until very frothy and opaque. Raise speed to high and beat until whites just begin to stand in soft peaks; be careful not to overbeat. Meanwhile, return syrup to burner and reheat just to boiling. Beating w Beat in vanilla and coffee mixture until evenly incorporated. Sift powdered sugar and cocoa onto a sheet of wax paper. A bit at a time, whisk into egg-white mixture. Whisk in melted chocolate just until smoothly incorporated.
Frost cake immediately, or store frosting airtight for up to 48 hours. Frosting may soften and gradually deflate upon longer standing.