Prepare the Cake Batter:

• Preheat your oven to 350°F (175°C). Grease and flour a heart-shaped cake pan (or use a square and round pan to create a heart shape).
• In a medium bowl, sift together flour, baking powder, baking soda, and salt.
• In a large bowl, beat butter and sugar until light and fluffy. Add eggs one at a time, beating well after each addition. Stir in vanilla extract.
• Gradually add the dry ingredients to the wet ingredients, alternating with buttermilk, beginning and ending with the dry mixture. If desired, mix in red food coloring for a festive look.

Bake the Cake:

• Pour the batter into the prepared pan(s) and smooth the top. Bake for 30-35 minutes, or until a toothpick inserted in the center comes out clean. Let the cake cool in the pan for 10 minutes, then transfer it to a wire rack to cool completely.

Make the Frosting:

• Beat the butter until creamy. Gradually add powdered sugar, one cup at a time, mixing well. Stir in vanilla extract and heavy cream until the frosting reaches a spreadable consistency. Add food coloring if desired.

Assemble the Cake:

• If using a square and round pan, cut the round cake in half and align the flat sides with the edges of the square cake to form a heart shape.
• Frost the cake evenly with the buttercream, smoothing it with an offset spatula. Decorate with sprinkles, fresh fruit, or edible flowers.