In a medium bowl, combine 2 cups of graham cracker crumbs with 1/3 cup granulated sugar. Pour in the melted salted butter (2/3 cups) and stir until the mixture looks like wet sand. Press this evenly into the bottom of your 9-inch springform pan, creating a firm base. Place it in the refrigerator while you prepare the filling to let it set.
In a large mixing bowl, whisk together 8 ounces of softened cream cheese, 1 teaspoon vanilla extract, and 3.4 ounces of vanilla instant pudding mix until smooth and creamy. This mixture will form the flavorful base of your cheesecake filling.
In a separate bowl, whip 2 cups of heavy cream until stiff peaks form. Gently fold the whipped cream into the pudding and cream cheese mixture, combining them thoroughly without deflating the cream. This creates a light, airy texture for the filling.
Peel and slice 3 to 4 medium bananas into thin rounds. Carefully fold half of the banana slices into the cheesecake batter. In another bowl, beat together 16 ounces of softened cream cheese, 1 teaspoon vanilla extract, 2/3 cups sour cream, and 3/4 cup powdered sugar until smooth. Gently combine this with the pudding-cream mixture for extra richness and creaminess.
Pour half of the cheesecake batter over the chilled graham cracker crust. Layer the remaining banana slices evenly on top, then cover with the rest of the batter. Smooth the surface with a spatula. Refrigerate the cheesecake for at least 4 hours, or overnight for best results.
Before serving, whip the remaining 1 cup of heavy cream with 1/2 cup powdered sugar until stiff peaks form. Spread or pipe this luscious topping over the chilled cheesecake for a stunning finish.
For an extra touch, garnish with extra banana slices or a sprinkle of crushed graham crackers. Slice carefully with a warm knife, serve, and enjoy the creamy delight of your homemade Banana Cream Cheesecake!