Add the powdered sugar, vanilla, salt and 1 T of milk to the bowl. Beat until well combined. Add more milk, 1/2 Tablespoon at a time, until the frosting reaches a consistency where it can be easily spread, but still retains it's shape.
Cut the large marshmallows in half diagonally with a sharp kitchen shears or chef's knife. Place the pink sanding sugar into a bowl and dip the freshly cut side of the marshmallow into the pink sugar to create the bunny ears.
Add two of the mini marshmallow halves directly below the heart to create the bunny muzzle. Then place two of the large marshmallow halves at the top of each cookie to create the ears. Then place two black pearl sprinkles between the ears and nose to create the bunny eyes.