Ingredients:
- 325g all-purpose flour
- 300g granulated sugar
- 1.5 tsp baking powder
- 0.5 tsp baking soda
- 0.5 tsp fine sea salt
- 170g unsalted butter, room temperature and cubed
- 3 large eggs, room temperature
- 120ml full-fat buttermilk, room temperature
- 60ml neutral oil (grapeseed or vegetable)
- 2 tsp pure vanilla extract
- 0.25 tsp pink gel food coloring
- 450g unsalted butter, softened
- 720g powdered sugar, sifted
- 45ml heavy cream
- 1 tbsp pure vanilla bean paste
- 1 pinch salt
Instructions:
- Preheat oven to 350°F (180°C). Grease one 8-inch square pan and one 8-inch round pan, and line both with parchment paper.
- In a stand mixer, combine flour, sugar, baking powder, baking soda, and salt. Add 170g of cubed butter and mix on low speed until the mixture reaches a texture resembling wet sand with no large butter chunks visible.
- In a separate bowl, whisk together eggs, buttermilk, oil, vanilla extract, and pink gel coloring. Gradually pour into the flour-butter mixture. Scrape the bowl and mix for another 30 seconds until the batter is smooth and a consistent soft pink.
- Divide the pink batter evenly between the square and round pans. Bake for 35 minutes or until a skewer comes out clean. Allow to cool completely.
- Prepare the buttercream by beating 450g softened butter for 5 minutes until pale and airy. Gradually add powdered sugar, heavy cream, vanilla bean paste, and a pinch of salt. Whip until light and fluffy.
- Assemble the heart: Place the square cake on a board like a diamond. Cut the round cake exactly in half to create two semi-circles. Attach the flat side of each semi-circle to the top two sides of the square cake using a bit of frosting to create a heart shape.
- Apply a crumb coat of vanilla buttercream, chill for 20 minutes, then apply a final smooth layer of frosting over the entire heart cake.