1 box chocolate cake mix (recommended: Duncan Hines) 1/2 cup coffee liqueur 2 cups fudge sauce, recipe follows, or 1 (16-ounce) jar fudge sauce 3 chocolate covered toffee candy bars, broken into pieces 1 1/2 cups heavy cream whipped and sweetened with 1/3 cup sugar
Prepare the cake according to the package directions for a 9 by 13-inch cake. Cool thoroughly.
Prick the entire top of the cake with a fork. Pour coffee liqueur over the cake and allow it to soak in. Wrap the cake with plastic and refrigerate for at least 3 hours. Slice the cake into 1-inch thick pieces.
Line the bottom of a large glass bowl with a single layer of cake. Pour 1/4 of the fudge sauce over the cake, top with 1/4 of the candy bar-bits then 1/3 of the whipped cream. Repeat layering 2 more times ending with fudge sauce and candy bits. Refrigerate until ready to serve.
To make the sauce: Melt the German chocolate with the butter in a saucepan over very low heat. Stir in the powdered sugar, alternating with evaporated milk and blending well. Stirring constantly, bring the mixture to a simmer over medium heat. Simmer until the mixture becomes thick and creamy, about 8 minutes. Stir in the vanilla.