Prepare the Buttercream Frosting: In a large bowl, cream the shortening and butter together with an electric mixer. Add vanilla, and gradually mix in the sugar, one cup at a time. When the mixture is dry, add milk and beat until light and fluffy
Mash the Cake: Tear the cake into small pieces and mix it with the buttercream frosting using your hands. (Plastic gloves make this step easier!)
Layering Time: In a large bowl or sundae glass, start by adding a layer of the cake mixture at the bottom.
Add Pudding: Next, add a layer of banana pudding (or chocolate pudding). Continue layering, alternating between the cake mixture and pudding until the bowl is filled.
Optional Toppings: If desired, top waith whipped cream and shaved chocolate for extra flavor and texture. (This is optional, but it’s a great finishing touch.)
Chill & Serve: Refrigerate the dessert for at least 2 hours to allow the layers to set and the flavors to meld.