Preheat oven to 350 degrees F (175 degrees C). Grease a 9-inch pie dish.
Beat egg whites and baking powder in a glass or metal bowl until foamy. Gradually add sugar and vanilla extract, continuing to beat until stiff peaks form. Lift your beater or whisk straight up: the egg white mixture will form sharp peaks.
Fold graham cracker crumbs, 1/2 cup coconut, and 1/2 cup macadamia nuts into egg white mixture; pour into the prepared pie dish.
Bake in the preheated oven until set, about 30 minutes. Cool completely.
Spread whipped topping over cooled pie and sprinkle 1/4 cup coconut and 1/4 cup macadamia nuts over whipped topping.