Preheat your oven to 350°F (175°C) and prepare two 9-inch round cake pans by greasing and dusting with flour.

In a medium bowl, whisk together the flour, baking powder, and salt. Set aside.

In a large mixing bowl, cream the softened butter and granulated sugar until light and fluffy.

Add the eggs one at a time, mixing well after each addition, then stir in the vanilla extract.

Gradually add the dry ingredients to the wet mixture, alternating with the milk, and mix until just combined.

Divide the batter evenly between the prepared cake pans and smooth the tops.

Bake for 25-30 minutes, or until a toothpick inserted in the center comes out clean.

Let the cakes cool in the pans for 10 minutes, then transfer to a wire rack to cool completely.

For the frosting, beat the softened butter until creamy, then gradually add powdered sugar and milk, mixing until fluffy.

Layer the cooled cakes with frosting in between, then frost the top and sides of the cake.

Decorate with Capricorn-themed decorations, edible glitter, or fresh fruits as desired.