1/4 cup, or half a stick of butter at room temperature 1/4 cup of vegetable shortening 3 cups of powdered sugar 2 tsp vanilla extract 1 1/2tbsp of milk gel food coloring stand mixer with whisk attachment measuring cups and spoons

Let butter sit out and get to room temperature, this takes 45 minutes.
Combine all of the ingredients in your stand mixer , mix until combined, then add food coloring and continue to mix.
Spread on cooled cookies, store in fridge for five days.