1-First Step: Prepare your workstation and ingredients. It is crucial that your butter is softened to room temperature before you begin. If the butter is too cold, the frosting will be lumpy. If it is too melty, the frosting will be too soft to hold shape. Sift your powdered sugar to remove any lumps. Measure out your milk and vanilla extract so they are ready to pour.

2-Second Step: Cream the butter. Place the softened butter in a large mixing bowl or the bowl of a stand mixer fitted with a paddle attachment. Beat the butter on medium speed for about 1 to 2 minutes. You want it to become pale yellow and creamy. Scrape down the sides of the bowl with a spatula to ensure all the butter is being evenly mixed.

3-Third Step: Incorporate the sugar. Turn the mixer to low speed. Gradually add the sifted powdered sugar, one cup at a time. Adding it slowly prevents a cloud of sugar dust from flying out of the bowl. Once all the sugar is added, the mixture will look dry and crumbly. This is normal. Keep the mixer on low until the sugar is mostly absorbed into the butter.

4-Fourth Step: Add liquids and flavor. With the mixer still on low, pour in the vanilla extract and 2 tablespoons of the milk. Once the liquids are incorporated, increase the speed to medium-high. Beat the frosting for 3 to 5 minutes. This step is critical because it whips air into the mixture, making it light and fluffy. Stop the mixer and check the consistency. If the frosting is too stiff to spread, add another tablespoon of milk. If it is too thin, add a little more powdered sugar. Continue beating until the frosting is smooth, creamy, and holds soft peaks.

5-Final Step: Fold in the rainbow chips. Turn the mixer off or remove the bowl from the stand. Gently fold in the 1/2 cup of rainbow sprinkles or chocolate chips using a spatula. Mix by hand rather than with the mixer to prevent crushing the chips. Fold just until the chips are evenly distributed.