Preheat your oven to 350°F (175°C) and grease and flour two 9-inch round cake pans.
Whisk together the flour, baking powder, and salt in a medium bowl.
Beat butter and sugar in a large bowl until light and fluffy, then add eggs one at a time and mix in vanilla.
Gradually add the dry ingredients to the wet ingredients, alternating with milk, and mix until just combined.
Divide the batter evenly between the prepared pans and bake for 25-30 minutes, or until a toothpick comes out clean.
Cool the cakes in the pans for 10 minutes, then transfer to a wire rack to cool completely.
For the frosting, beat butter until smooth, then gradually add powdered sugar, milk, vanilla, and salt. Beat until fluffy.
Once the cake layers are cool, spread frosting between the layers and on top of the cake. Decorate as desired with fondant, fruit, nuts, or sprinkles