In top of double-boiler, combine chocolate and hot water. Stir constantly over hot, not boiling water, to melt chocolate. Add 1/2 cup sugar; cook stirring, 2 minutes, to dissolve. Remove from hot water. Cool to lukewarm. Sift flour with soda and salt.

Preheat oven to 350 degrees. Grease and flour two 9-inch round layer cake pans. In large mixer bowl, at medium speed, beat butter until fluffy. Gradually beat in 1 1/4 cups sugar, beating until very light and fluffy, about 5 minutes. Add vanilla. Add eggs, one at a time; beat well after each addition, scraping down side of bowl and beaters.

At low speed, add flour mixture (in fourths) alternately with milk (in thirds); begin and with flour. Beat just to blend. With scraper, blend in chocolate. Turn into pans. Bake 25 minutes, or until surface springs back when gently pressed with finger. Do not over bake. Cool 10 minutes. Loosen sides with spatula. Remove layers; cool on racks.

In medium bowl, combine cream, sugar, cocoa, salt and coffee. Refrigerate, covered, 1/2 hour. Beat with rotary beater until stiff. Refrigerate. With long, thin-bladed knife, split layer in half to make four. Place layer, cut side up, on plate. Spread 2/3 cup mocha filling. Repeat twice. Top with last layer, cut side down.

Turn 1 1/4 cup mocha filling into pastry bag with No. 2 star tip. With metal spatula, frost top and side of cake smoothly with remaining mocha. With pastry bag, make ruffling around top and base.

Melt 1/2 square semi-sweet chocolate. Dip the ends of 14 whole unblanched almonds into chocolate. Arrange on cake.