Preheat your oven to 350°F (175°C) and grease two 9-inch round cake pans.

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

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

Add eggs, one at a time, mixing well after each addition.

Stir in the vanilla extract.

Gradually add the dry ingredients, alternating with milk, starting and ending with the flour mixture.

Fold in the rainbow sprinkles gently to maintain their color.

Pour the batter evenly into the prepared cake pans.

Bake for 30-35 minutes, or until a toothpick inserted comes out clean.

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