Preheat oven to 350 degrees. Line a baking sheet with parchment paper
In a large bowl, cream together butter and sugar until creamy. Beat in eggs, one at a time, followed by lime zest.
In a medium bowl, whisk together flour, baking powder, baking soda and salt. Stir flour mixture into the butter mixture, mixing only until no streaks of flour remain. Stir in white chocolate chips and macadamia nuts.
Drop dough by tablespoonfuls onto prepared baking sheet, making approximately 1" balls and leaving some room for the cookies to spread
Bake for 10-12 minutes, until cookies begin to brown slightly around the edges.
Cool for 5 minutes on baking sheet and remove to a wire rack to cool completely before storing. Makes about 3 dozen