Southern-Style Caramel Cake

INGREDIENTS: For the cake: 1 cup of sour cream. 21/2 cups of sugar. 1/3 cup of vegetable oil. 6 large eggs, plus 2 egg yolks, at room temperature. 1/2 teaspoon of salt. 2 sticks of unsalted butter, at room temperature. 1 teaspoon of baking powder. 3 cups of flour for sifted cake. 2 tablespoons vanilla extract.