Grease a cookie sheet; set aside. Stir together flour, cocoa powder, and sugar. In a saucepan bring water, butter, and salt to boiling; stir until butter melts. Add flour mixture all at once to boiling mixture, stirring vigorously. Cook and stir until mixture forms a ball. Cool 10 minutes.

Add eggs, one at a time, beating with a wooden spoon about 1 minute after each addition or until smooth.

Spoon the batter into a pastry bag fitted with a large plain round tip (1/2- to 1-inch opening). Pipe strips of batter (measuring about 4 inches long, 1 inch wide, and 3/4 inch high) 3 inches apart onto prepared cookie sheet.

Bake in a 400 degree F oven for 33 to 35 minutes or until puffy. Remove from cookie sheet; cool on a wire rack.

Up to 2 hours before serving, cut off tops of eclairs. Remove soft dough from inside. Pipe whipped cream into eclairs. Replace tops. Chill until serving time. If desired, top with Bittersweet Hot Fudge Sauce and dust with powdered sugar. Makes 12 eclairs.

Coarsely chop 3 ounces semisweet chocolate and 1 ounce unsweetened chocolate. In a medium saucepan combine the chocolates, 1/2 cup half-and-half or light cream, and 1/4 cup sugar. Bring to boiling; reduce heat. Simmer mixture, uncovered, over low heat about 2 minutes or until mixture is creamy, stirring frequently. Remove from heat; stir in 1/4 teaspoon vanilla. Serve warm. Makes about 1 cup.

Bake and cool eclairs; freeze in an airtight container up to 2 months. Thaw 2 hours at room temperature before filling.