In a stand mixer fitted with a paddle attachment, beat butter and cream cheese together until light and fluffy.
Slowly add powdered sugar. Mix until combined and fluffy.
Add vanilla and milk. Mix until combined.
Add a few drops of pink food coloring. Mix until you get desired color.
Prepare a piping bag with a star tip. Add 1/2 cup of icing to the bag and set aside.
Place one layer onto a cake plate. Using an offset spatula, spread 1/2 cup of frosting on the cake.
Turn the second layer upside down (so the bottom is face up) and gently place it on top of the first layer.
Spread another 1/2 cup of frosting on the cake. Turn the third layer upside down and gently place it on top of the second layer.
Create a thin crumb layer all around the cake. Place cake in the fridge for 30 minutes.
Use the remaining frosting to frost the rest of the cake. Start with a generous amount on the top and work your way to the sides.
Add conversation hearts to the side of the cake and on top.
Pipe border around the bottom of the cake.