Preheat your oven to 350°F and grease two 9-inch round cake pans.
Mix the flour, baking powder, and salt in a bowl.
In a separate bowl, beat the eggs and sugar until fluffy.
Melt the butter in the milk and add to the egg mixture along with the vanilla extract and oil.
Combine the wet and dry ingredients until just mixed.
Divide the batter evenly between the prepared pans.
Bake for about 30 minutes or until a toothpick comes out clean.
Cool the cakes in the pans for 10 minutes, then turn out onto a wire rack to cool completely.
For the frosting, beat the softened butter until creamy, then gradually add powdered sugar and vanilla, adding milk as needed for desired consistency.
Frost the cooled cake layers and serve.