Bake your favorite brownie mix or recipe and bake according to the temperature listed. To make the brownies thinner for stacking, bake them in a larger pan than the recipe calls for, and alter the baking time accordingly. Instead of an 8x8 pan that my brownie mix called for, I used a 9x13 pan, and reduced the baking time by about half, then watched them closely until they were done. Let them cool completely.
While the brownies are baking, make your frosting by beating the powdered sugar and softened butter together with a mixer. Slowly add the half and half in until you have the right consistency--not too thick, and not too thin. Add the vanilla and salt, and beat well. Add as much food coloring as you want to achieve the right shade of pink.
Once the brownies are cooled, use the round biscuit cutter to cut out as many hearts as possible. Remove them, and place them on a large platter or plate. In half of the circles, use the smaller heart cookie cutter to cut out a heart in the center of the circle. Remove the smaller hearts and set them aside. (You can frost them and serve them separately!)
Frost the full circle brownies, then place the brownies with the hearts cut out on top. Sprinkle with powdered sugar!