Preheat oven to 350 degrees. Grease and flour 2 9-inch or 3 7-inch round cake pans. Line bottoms with parchment paper (see link in post). Reserve.

In a large bowl, beat eggs for 2-3 minutes on medium speed until they turn a pale yellow. Add in sugar and beat until well combined. Add in mayonnaise, coffee, and vanilla and beat until mixture is well blended.

In a medium bowl whisk together flour, baking soda, baking powder, salt and cocoa powder. Add flour mixture in 4 additions, mixing well between additions. Stir in chocolate chunks.

Divide batter evenly between prepared pans or until pans are half full. Do not overfill. Bake at 350 for 25 - 30 minutes or until a cake tester comes out clean. Allow to cool in pans on wire racks for 30 minutes. Then remove from pans and allow to cool until just slightly warm. Wrap warm cakes in plastic wrap and place in freezer while you prepare the cream cheese toffee bit filling and the buttercream & caramel frosting.

Beat together butter, cream cheese and vanilla until creamy. Slowly beat in confectioners sugar until well combined. Stir in toffee bits. Spoon 1/2 of mixture on top of one cake layer and spread evenly. Top with second cake and top with remaining filling then top with final cake layer.

Beat confectioners sugar and butter until well combined. Add in vanilla and cooled melted chocolate and stir until combined. Mixture will be thick. Gradually add in milk until desired consistency is reached. Lightly frost all edges of cake. If cake is sticking to frosting, chill before adding second layer. If frosting becomes too thick add another tablespoon of milk. Completely frost sides and top of cake.

Place unwrapped caramels in microwave safe bowl. Add milk and microwave on HIGH for 1 minute; stir. Microwave in 30 second intervals, stirring in between until fully melted. Allow to cool for 5 minutes. Spoon onto top of cake. Tip cake slightly to encourage run off.

Sprinkle top with shaved chocolate and toffee bits.