Make the Fondant Hearts (Do this 1-2 days ahead)

1. To make the fondant hearts, break off 6 pieces of fondant that are about the size of a golf ball. Leave one white and color the others – one yellow, one pink, one orange, one purple and one green (with a combination of green and blue color). I tried to match the colors close to conversation heart colors.
2. Roll out one color of fondant at a time and use a heart shaped cutter to cut out the hearts. Set the hearts aside to dry out and firm up for a day or two.
3. Once dry and firm, use the food writer pen to write conversation heart sayings onto the hearts.

Make the Conversation Heart Milk

1. Add the warm milk and conversation hearts to a large jar or measuring cup and stir together. The candies will slowly dissolve in the milk. Let it sit, stirring every once in a while, until completely dissolved. It could take about an hour or so. You can do this a day or so ahead and refrigerate the milk until you need it.

Make the Cupcakes

1. Preheat oven to 350°F (176°C) and prepare a cupcake pan with cupcake liners.
2. Combine the flour, baking powder and salt in a medium sized bowl and set aside.
3. In a large mixing bowl, cream butter and sugar together until light in color and fluffy, about 2-3 minutes. Do not skimp on the amount of creaming time.
4. Add the sour cream and vanilla extract and mix until well combined.
5. Add half of the dry ingredients to the batter and mix until mostly combined. Slowly add the conversation heart milk and mix until well combined. Add the remaining dry ingredients and mix until well combined and smooth. Scrape down the sides of the bowl as needed to be sure all ingredients are well incorporated. Do not over mix the batter. Set aside.
6. Add the egg whites to a large mixing bowl and whip on high speed until soft peaks form.
7. Carefully fold the egg whites into the rest of the cake batter in two parts, until no streaks of egg white remain.
8. Fill the cupcake liners a little more than halfway full. Bake for 15-17 minutes, or until a toothpick inserted comes out with a few crumbs.
9. Remove cupcakes from oven and allow to cool for 2-3 minutes, then remove to cooling rack to finish cooling.

Make Fondant Hearts and Buttercream

1. While the cupcakes cool, make the frosting. Add the butter to a large mixing bowl and beat until smooth.
2. Add half of the powdered sugar and beat until well combined and smooth.
3. Add the vanilla extract and 2 tablespoons of conversation heart milk and mix until smooth.
4. Add the remaining powdered sugar and mix until smooth.
5. Add the remaining milk, as needed, and a pinch of salt and mix until well combined.
6. Divide the buttercream into 5 bowls. Color one yellow, one pink, one orange, one purple and one green (with a combination of green and blue color). I tried to match the colors close to conversation heart colors.
7. To make the swirl frosting, add each color of frosting to a ziplock bag. Then lay a piece of clear wrap out on the table. Trim the corner off of each ziplock bag. Pipe a thick row of each color of frosting side-by-side onto the clear wrap.
8. Fold the clear wrap over into a long log. Twist both ends closed and trim off one end so that the frosting is right at the edge.
9. Put the log into a piping bag with the open end of the log going into the piping tip. I used piping tip Ateco 847.
10. Pipe swirls of frosting onto the cupcakes and top with the fondant conversation hearts or actual conversation heart candies.