1. Preheat oven to 350°. Grease a 9-in. pie plate.
2. In a mixing bowl, combine 1-3/4 cups cake mix, egg and 1 tablespoon butter until combined. Turn onto a floured surface; knead until a smooth dough forms.
3. Roll out the pie crust to fit the prepared pie plate. Flute the edge of the crust, the generously prick the bottom several times with a fork.
4. Bake until golden brown, 12-15 minutes. Cool crust in pan on a wire rack.
5. While the crust is baking, whisk the milk and pudding mix together for 2 minutes.
6. Fold in banana and half of the whipped topping. Pour the mixture into the cooled crust.
7. Top with remaining whipped topping. Refrigerate at least 3 hours
8. While the pie is chilling, mix remaining cake mix, peanut butter and remaining butter until the mixture is crumbly. Transfer to a parchment-lined rimmed baking pan. Bake until golden brown, 14-18 minutes, stirring once. Cool completely.
9. Just prior to serving, top the pie with additional sliced banana and some of the crumb topping (save additional crumb topping for another use). Yield: 10 servings.

Sprinkle the remaining topping over ice cream to make a delicious treat.
Working with pastry dough quickly will keep it from becoming too soft or sticky while you are rolling it out and fluting it.
Our family loves the addition of toasted coconut! Stir 1/2 cup into the filling, then top the pie with another 1/2 cup of sweetened coconut flakes.

Nutritional Facts (without the coconut)
1 piece: 394 calories, 16g fat (8g saturated fat), 30mg cholesterol, 526mg sodium, 55g carbohydrate (35g sugars, 1g fiber), 6g protein.