Heat margarine, chocolate, milk, apricot preserves, and espresso crystals in small saucepan, whisking frequently, until chocolate is almost melted.

Remove pan from heat; continue whisking until chocolate is melted and mixture is smooth. Whisk in egg yolk and vanilla; add Equal, whisking until smooth.

Beat egg whites and cream of tartar to stiff peaks in large bowl. Fold chocolate mixture into egg whites; fold in combined flour and salt.

Lightly grease bottom of 9-inch round cake pan and line with parchment or baking paper. Pour cake batter into pan. Bake in preheated 350-degree oven until cake is just firm when lightly touched, 18 to 20 minutes, and toothpick comes out clean (do not overbake). Carefully loosen side of cake from pan with small sharp knife, which will keep cake from cracking as it cools. Cool cake completely in pan on wire rack; refrigerate until chilled, 1 to 2 hours.

Remove cake from pan and place on serving plate. Spread with Rich Chocolate Glaze, if desired. Garnish with light whipped topping, chocolate drizzle, and/or raspberries, if desired.

This recipe yields 12 servings. Serving size: 1 slice.

Exchanges Per Serving: 2 Fat, 1/2 Bread.

Nutrition Facts: Calories 139; Total Fat 11g; Cholesterol 18mg; Sodium 108mg; Carbohydrate 11g; Protein 3g.