Preheat your oven to 350°F (175°C). Grease and flour three 8-inch round cake pans.

In a large mixing bowl, cream together unsalted butter and granulated sugar until light and fluffy, about 3 to 5 minutes.

Add eggs, one at a time, beating well after each addition, then mix in vanilla extract until well combined.

In a separate bowl, whisk together all-purpose flour, baking powder, baking soda, and salt. Gradually add to the creamed mixture, alternating with buttermilk.

Divide the batter among prepared pans and bake for 25-30 minutes or until a toothpick comes out clean.

Prepare cheesecake center by beating cream cheese and sugar until smooth, then add eggs, vanilla extract, and sour cream, mixing until combined.

Pour cheesecake mixture over the first cake layer and bake for an additional 15-20 minutes until set but slightly jiggly in the center.

For frosting, combine evaporated milk, sugar, egg yolks, and butter in a saucepan, stirring until thickened, about 10-15 minutes.

Remove from heat and stir in vanilla extract, shredded coconut, and chopped pecans, then allow to cool completely.

Assemble cake layers by placing one layer on a serving plate, add cheesecake, then second cake layer, and frost generously.

Allow the cake to set for at least 30 minutes before slicing and serving.