In the bowl of a stand mixer fitted with a paddle attachment, or in a large bowl with a hand-held mixer, mix all of the ingredients on low speed until it starts to come together.

Increase speed to high and beat for 4-5 minutes until frosting is fluffy, pausing once or twice to scrape the bowl down.

(Optional Step) The frosting will be very airy with lots of bubbles. To achieve a smooth frosting, beat it with a wooden spoon by hand for 2-3 minutes. This will push all of those air bubbles out.

Use frosting as desired to cover cakes, cupcakes, cookies, etc. This is enough frosting for a double layer 8 or 9-inch cake, 2 dozen cupcakes, or 2 dozen 4-inch cookies.

Store frosting at room temperature for 1-2 days, in the fridge for up to 2 weeks or in the freezer for up to several months.