Preheat oven to 350°F (175°C).
In a mixing bowl, combine gluten-free flour, sugar, shredded coconut, chopped macadamia nuts, baking powder, and salt.
In another bowl, whisk together eggs and vanilla extract.
Combine wet and dry ingredients until a dough forms.
Divide the dough in half and shape each half into a log about 10 inches long and 2 inches wide. Place the logs on a baking sheet lined with parchment paper.
Bake for 25-30 minutes, until the logs are golden brown. Remove from the oven and let cool for 10 minutes.
Reduce oven temperature to 325°F (165°C). Using a serrated knife, cut the logs into ½-inch slices. Place the slices cut side down on the baking sheet.
Bake for another 10-15 minutes, until the biscotti are crisp. Let cool completely before serving.