Preheat oven to 350 degrees F (175 degrees C). Grease an 8x8-inch square pan and an 8-inch round pan.
Beat white sugar and 1 cup butter together in a bowl with an electric mixer until creamy and smooth. Mix eggs, 1 tablespoon vanilla extract, and almond extract into creamed butter mixture. Stir baking powder and baking soda into butter mixture until just combined.
Stir 1 cup flour into butter mixture until just combined. Add 2/3 cup milk into butter-flour mixture; mix well. Continue adding 1 cup flour and 2/3 cup milk, alternating until all the flour and milk are used and batter is smooth. Pour batter into the 2 prepared pans.
Bake in the preheated oven until a toothpick inserted in the center of each cake comes out clean, 30 to 40 minutes. Cool cakes completely before removing from pans, at least 2 hours.
Beat confectioners' sugar, 1 cup butter, and 2 teaspoons vanilla extract together in a bowl with an electric mixer until icing is fluffy and smooth.
Remove cakes from pans and slice round cake in half. Lay the square cake on a work surface so it resembles a diamond-shape. Lay 1 round cake half on the top left side of the 'diamond' cake. Lay the second round cake half on the top right side of the 'diamond' cake, creating a 'heart-shaped' cake on top. Spread icing over the assembled cake.
