Preheat the oven to 350°F (175°C). Grease and flour the two 8-inch round cake pans.
In a large mixing bowl, combine the softened butter and granulated sugar. Beat until light and fluffy using an electric mixer.
Add the eggs one at a time, mixing well after each addition. Then, stir in the vanilla extract.
In a separate bowl, whisk together the flour, baking powder, and salt. Gradually add this dry mixture to the wet ingredients, alternating with the milk. Mix until just combined.
Divide the cake batter evenly between the two prepared pans. Bake in the preheated oven for 25 minutes or until a toothpick inserted in the center comes out clean.
Once baked, remove the cakes from the oven and let them cool in the pans for about 10 minutes. Then, transfer them to a cooling rack to cool completely.
Once the cakes have cooled, use a serrated knife to level the tops if necessary. Place one cake layer on your serving platter.
Spread a layer of buttercream frosting over the first cake layer. Place the second cake layer on top and frost the top and sides of the entire cake.
Divide the remaining frosting into smaller bowls and color each with food coloring. Use a piping bag to decorate the cake as desired, adding swirls, flowers, or other designs.
Finish by adorning the cake with edible decorations like chocolate eggs, bunny toppers, and sprinkles to give it that festive Easter look.