In a mixing bowl, beat butter with electric mixer on low speed or by hand until creamy, then blend in egg. Slowly add dry cookie mix and blend until all incorporated.
Gather dough into a ball and flatten into a disc. Wrap in plastic and freeze 20 minutes or until firm. Preheat oven to 350 degrees. Flour a flat surface and roll out dough to 1/4” thick.
Cut cookies from dough using a 2” round cutter and place 1” apart on cookie sheets lined with parchment paper. Bake 12-14 minutes or until edges are slightly brown. Cool cookies completely on a wire rack.
To make the frosting, in a large bowl blend together the butter and yogurt then add the dry frosting mix and blend a minute more until smooth and creamy.
Divide frosting and use the natural dyes to color the frosting. Place each color of frosting into a piping bag, and decorate the cookies as your favorite emoji.