Preheat the oven to 325°F (163°C). Beat cream cheese until smooth, then mix in sugar, eggs, vanilla, and sour cream. Pour into a greased 9-inch springform pan.
Bake for 35–40 minutes until the center is set but slightly jiggles. Cool to room temperature, then chill for 2+ hours.
Increase oven temperature to 350°F (175°C). Cream butter and sugar until fluffy. Add egg whites, then vanilla. In a separate bowl, mix flour, baking powder, and salt.
Add dry ingredients and milk to the butter mixture, alternating between the two. Divide batter between two greased 9-inch pans and bake for 25–30 minutes. Cool on a wire rack.
In a saucepan, whisk evaporated milk, brown sugar, egg yolks, and butter. Cook over medium heat for 10–12 minutes, stirring constantly, until thickened. Remove from heat and stir in vanilla, coconut, and pecans. Let cool to room temperature.
Place one cake layer on a plate. Add the chilled cheesecake on top, followed by the second cake layer. Spoon the cooled coconut-pecan topping over the cake, allowing it to drip down the sides. Optionally, drizzle with warm caramel before serving.