Preheat oven to 350°F (175°C). Grease and line three 8-inch pans.
Mix dry ingredients; cream butter and sugar. Add eggs, vanilla, and bananas. Alternate dry and buttermilk; divide batter and bake for 22-26 minutes. Cool completely.
Prepare filling by mixing pudding with milk; fold in whipped cream. Chill.
Whip cream, powdered sugar, and vanilla for frosting. Assemble cake with layers, spread filling, frost, and decorate with bananas and wafers.
Notes
Ensure all ingredients are at room temperature for best results.