FOR THE COOKIES: – Zest of 1 lemon (about 1 tablespoon) – Zest of 1 lime (about 2 teaspoons) – Zest of 1 orange (about 2 tablespoons) – 2 tablespoons fresh lemon juice – 2 tablespoons fresh lime juice – 2 tablespoons fresh orange juice – 3 cups (360g) all-purpose flour – 1 teaspoon baking powder – 1/2 teaspoon salt – 1 cup (226g) unsalted butter, softened – 1 cup (200g) granulated sugar – 2 large egg – 1 teaspoon vanilla extract FOR THE GLAZE: – 2 cups (220g) powdered sugar – 2 tablespoons fresh lemon juice – 1 tablespoon fresh lime juice – 1 tablespoon fresh orange juice – Zest of lemon, lime, and orange, for garnish (optional)