Prepare the Butter and Juice: Begin by taking your slightly softened sweet cream salted butter and placing it into a mixing bowl. Pour in 2 tablespoons of maraschino cherry juice. Mix these on medium speed for about 2 minutes until fully combined.
Add Powdered Sugar: Gradually incorporate 4 cups of powdered sugar into the bowl while covering the mixer with a towel. Mix on low speed until the sugar is just combined, about 30 seconds.
Whip for Fluffiness: Increase the mixer speed to medium-high and continue to beat for 30-45 seconds until the frosting becomes light and fluffy.
Thicken the Frosting: Add 1 tablespoon of cornstarch to the mixture and mix until fully combined.
Taste and Adjust: Before folding in the cherries, taste the frosting to see if it’s to your liking. If desired, add a pinch of salt.
Prepare the Cherries: Finely dice 6-8 maraschino cherries, ensuring they are dried off, then gently fold them into the frosting.
Final Mix and Serve: Give the frosting a final gentle stir, then use to decorate cakes, cupcakes, or brownies.