Pour the lemonade into a small saucepan and sprinkle the gelatin on top. Let sit for a couple of minutes to soften.
Heat over a low flame, stirring constantly, for about 5 minutes. Make certain gelatin has completely dissolved.
Remove from the heat and, with a whisk, stir in vodka and sweetened condensed milk.
In six small bowls, pour 1/2 cup of mixture into each. Add several drops of food coloring to each until desired color is achieved. (For rainbow, use red, orange, yellow, blue, green and purple.)
Spray silicone mini muffin pans with Pam and then wipe clean with a paper towel.
Spoon 3/4 teaspoon of red into the bottom of each muffin cup. Refrigerate until set but still somewhat sticky. (10-15 minutes). Repeat with remaining colors. These will set up in less time than the red.
Refrigerate overnight. To serve, run a knife or small spatula around the outside of each and pop them out.
Right before serving, garnish with a small dollop of frosting and rainbow sprinkles.