Preheat your oven to 350°F (175°C). Grease and flour two 8-inch round cake pans or one heart-shaped pan if available. In a large bowl, cream together 1 cup room temperature unsalted butter and 1 1/2 cups granulated sugar until light and fluffy. Add 3 large eggs one at a time, beating well after each addition, then stir in 1 tsp vanilla extract.

In a separate bowl, whisk together 2 cups all-purpose flour, 2 tsp baking powder, and 1/2 tsp salt. Gradually add the dry ingredients to the wet mixture, alternating with 3/4 cup whole milk, until just combined. Divide batter between prepared pans and bake for 25-30 minutes, or until a toothpick inserted in the center comes out clean. Cool in pans for 10 minutes, then turn out onto wire racks to cool completely.

If using round pans, level the cakes. To create a heart shape, cut one circle in half, and attach the flat sides to the top and side of the other whole circle using a bit of frosting as glue. Carve into a heart shape if needed.

For the buttercream, beat 1 cup room temperature unsalted butter until creamy. Gradually add 4 cups powdered sugar, 1 tsp vanilla extract, and 2-4 tbsp milk as needed to reach a stiff, pipeable consistency. Tint with a few drops of food coloring.

Place the cake on a serving plate. Apply a thin layer of buttercream over the entire cake to lock in crumbs. Chill for at least 30 minutes.

Apply a smooth final layer of frosting over the crumb coat. This is your canvas for piping.

Using a Wilton tip 4B in a piping bag, pipe bold shell borders around the base and top edge of the cake. Rotate your wrist slightly for the vintage shell look.

Switch to a petal tip like 102, and pipe ruffle garlands along the sides by gently moving the bag back and forth in a U shape.

Overpipe the shells with a smaller star tip to add depth, following the Lambeth technique.

Place maraschino cherries on the peaks of the ruffles. Chill until ready to serve.