Zest the orange, lemon, and lime. Reserve about 2 teaspoons of zest and combine with 0.5 cup of sugar, mixing well and setting aside.

In a mixing bowl, beat softened butter and the remaining 1 cup sugar until creamy. Add the egg and beat until combined. Mix in flour, baking powder, baking soda, and zest mixture gradually.

Preheat oven to 350°F. Line a baking sheet with parchment paper. Form dough into ¾-1 inch balls and roll in the sugar-zest mixture to coat. Place on baking sheet.

Flatten each ball slightly with the bottom of a glass or your hand. Optionally, sprinkle a little extra sugar on top.

Bake for 10-12 minutes, until edges are golden. Remove and let cool on a wire rack.

Store in an airtight container for up to a week to enjoy these citrusy treats.