In a large mixing bowl, combine confectioners’ sugar, butter, lemon zest, lemon juice, lemon extract, and salt. Beat at low speed with a mixer until blended. Increase speed to high, and beat until light and fluffy. Add food coloring until desired shade of yellow is achieved.
Use immediately, or transfer to an airtight container, and refrigerate until needed. (Before using cold buttercream, let soften slightly at room temperature, and beat with a mixer for 1 minute.)
Recipe by TeaTime Magazine at https://teatimemagazine.com/lemon-ginger-cake-stacks-recipe/