Banana Pudding Cake

Name: Banana Pudding Cake
Prep time: 3 h
Cook time: 30 min
Total time: 3 h 30 min
Cuisine: Southern
Ingredients: 3 cups whole milk; 1/2 cup heavy whipping cream; 4 large eggs (room temperature); 2 egg yolks (room temperature); 2/3 cup granulated sugar; 6 tbsp cornstarch; 4 tbsp unsalted butter (cubed); 1 tbsp vanilla extract; 1 tsp banana extract; 1/2 tsp kosher salt; 2/3 cup vegetable oil; 1/3 cup unsalted butter (room temperature); 1 1/2 cups granulated sugar; 3 large eggs (room temperature); 2 3/4 cup all purpose flour (sifted); 1 1/2 tsp baking powder; 1 tsp salt; 1/2 tsp baking soda; 1 1/4 cup sour cream (room temperature ); 1/3 cup whole milk; 1 tbsp banana extract; 2 cups heavy whipping cream; 2 tbsp granulated sugar; 1 tsp pure vanilla extract; 1/2 tsp cream of tartar (optional, for stabilizing the whipped cream); Nilla wafers; 2 large bananas (sliced 1/4 inch thick)