On a piece of wax paper or a plate, finely zest the orange, lemon and lime.
Mix 2 t. of mixed zest with 1/2 c. sugar and set aside.
Combine butter and 1 c. sugar in a mixing bowl. Mix until creamy, about 2 min.
Add egg.
Add flour, baking powder and baking soda until well combined.
Slowly add remaining zest.
If your dough is dry, add 1 T. fresh lemon juice. Your dough should combine and form a ball. (I used 2 T. lemon juice.)
Form 1 in. balls and roll each one in sugar/zest mixture.
Slightly press each ball with the bottom of a glass to flatten just a bit.
Bake at 350 degrees for 10 - 11 min.
Cool.
Makes 3 dozen.