Prepare: Preheat oven to 350°F (175°C). Grease a heart-shaped pan or prepare two pans for the square/round method.
Mix dry ingredients: Whisk flour, baking powder, and salt in a bowl.
Cream butter and sugar: Beat until light and fluffy (about 3 minutes).
Add eggs: Mix in one at a time, then add vanilla.
Combine: Alternate adding dry ingredients and milk to butter mixture.
Color (optional): Add food coloring for a pink or red tint.
Bake: Pour into pan(s) and bake 30-35 minutes until toothpick comes out clean.
Cool: Let sit 10 minutes, then remove from pan and cool completely.
Make frosting: Beat butter until creamy, gradually add sugar, vanilla, and cream until smooth. Color as desired.
Assemble: If using two pans, arrange to form heart. Frost cake and decorate with sprinkles.
Serve: Cut into slices and enjoy your heart-shaped celebration!