Melt the butter in a pan under low heat and slowly add in the marshmallows until you have a liquid goo. Add some vanilla extract and 3 drops purple food coloring to the mixture.
Place rice krispies into a large bowl and quickly pour the purple marshmallow mix on top while hot. Blend and fold the mixture together until it is spread evenly through all the rice krispies. It solidifies rather quickly after it's off the heat so you need to work fast!!
After it is spread evenly,take the heart sprinkles and sprinkle them on top.
Take a metal spatula or something flat and press down on the surface of the rice krispies to even out lumps and ensures the sprinkles stay put.