1 (18.5 oz.) pkg. Chocolate cake mix
1 (14 oz.) can sweetened condensed milk
2 (1oz.) squares unsweetened chocolate, melted
½ cup cold water
1 (3.9 oz.) pkg. Instant chocolate pudding mix
1 cup heavy cream, whipped
Preheat oven to 350 degrees. Prepare and back cake mix according to package directions for two 9-inch layers. Cool and remove from pans. In a large bowl, mix together sweetened condensed milk and melted chocolate. Gradually stir in water, then instant pudding until smooth. Chill for at least 30 min. Remove the chocolate mixture from the refrigerator, and stir to loosen. Fold in whipped cream and return to fridge for at least another hour. Place one layer of cake onto a serving plate. Top it with 1 ½ cups of mousse, then cover with the remaining cake layer. Frost with remaining mousse and refrigerate until serving. Garnish with fresh fruit or chocolate shavings.