This is a simple version of a classic.
1 yellow cake mix
2 (3-oz) pkgs instant vanilla pudding mix
3 cups milk
Prepare cake according to pkg directions, baking it in (2) 8 or 9" round cake pans. Cool in pans for 10 minutes, then remove from pans and cool on wire racks. When completely cooled, cut each cake in half, so that you have 4 rounds.
Beat the vanilla pudding and milk together until thickened, and let set for 5 minutes. Spread half of the pudding mixture onto the top of 2 cake rounds. Top each with another cake round. Frost tops of cakes, with chocolate frosting.
2 ( 1-oz ) squares unsweetened chocolate
2 tbsp butter
1 1/2 cups pwd sugar
2 - 4 tbsp light corn syrup
3 tbsp milk
1 tsp vanilla
Melt the chocolate and butter together, stirring until melted. remove from heat and stir in the corn syrup, until well blended. Stir in the pwd sugar, milk and vanilla, mixing until smooth.