Sticky Toffee Banana Pudding

Name: Sticky Toffee Banana Pudding
Ingredients: 1 1/4 cups plus 3 tablespoons (or more) heavy whipping cream; 1/2 cup (packed) golden brown sugar; 1/2 cup dark corn syrup; 1/4 cup (1/2 stick) unsalted butter; 2 cups unbleached all purpose flour; 1 1/2 teaspoons baking powder; 3/4 cup (1 1/2 sticks) unsalted butter, room temperature; 2/3 cup (packed) dark brown sugar; 2 large eggs; 1 cup mashed very ripe bananas (2 to 3); 1 tablespoon dark rum; 1 1/2 teaspoons vanilla extract; Sliced bananas (optional); 8 x 8 x 2-inch nonstick metal baking pan