Begin by placing 1 cup of softened unsalted butter into a large mixing bowl or stand mixer. Beat the butter on high speed for 6 to 9 minutes until it becomes fluffy and pale in color.

Gradually sift in 4 cups of confectioner’s sugar while mixing on low speed. Once combined, increase to high and beat for an additional 3 to 4 minutes.

Add 2 teaspoons of lemon extract, 1 teaspoon of citric acid, and the zest from 1-2 lemons. Blend for 30 seconds, scrape down the sides, and mix again until well combined.

If too thick, add a tablespoon of milk or cream. For color, add yellow food coloring and mix on medium speed until consistent.

Once ready, use immediately to frost cakes or cupcakes, or store in an airtight container. Refrigerate for up to a week or freeze for a month.