Prepare the Cake BatterPreheat your oven to 350°F (175°C). Grease the cake pans with butter or non-stick spray and line the bottoms with parchment paper. In a medium-sized bowl, sift together the flour, baking powder, and salt. Set aside.
In a large bowl, use an electric mixer to beat the butter and sugar until light and fluffy (about 3-5 minutes).
Add the eggs one at a time, beating well after each addition. Then mix in the vanilla extract.
Gradually add the dry ingredients to the wet mixture, alternating with the milk. Start and end with the dry ingredients, mixing until just combined. Avoid overmixing to keep the cake tender.
Bake the CakeDivide the batter evenly between the prepared pans. Smooth the tops with a spatula. Bake for 30-35 minutes or until a toothpick inserted into the center comes out clean.
Remove the cakes from the oven and allow them to cool in the pans for 10 minutes before transferring them to a cooling rack. Let them cool completely before frosting.
Make the FrostingIn a large bowl, beat the softened butter until creamy. Gradually add the powdered sugar, one cup at a time, mixing well after each addition. Stir in the vanilla extract and 2 tablespoons of milk. If the frosting is too thick, add more milk, a teaspoon at a time, until you reach the desired consistency. Add food coloring if desired.
Assemble the CakePlace one cake layer on a serving plate. Spread a generous layer of frosting on top. Place the second cake layer on top and frost the top and sides of the cake evenly. Use an offset spatula for a smooth finish.
Decorate with sprinkles, candies, or edible decorations as desired.