Preheat your oven to 400 degrees. Prepare a rimmed baking sheet with cooking spray and set aside. In a large bowl combine the flour, baking powder, salt, and sugar. Using 2 forks, add butter and mix until it looks like crumbs. Add buttermilk or heavy cream and stir until blended. Add coconut and stir until incorporated. Roll the dough out on a lightly floured surface into a rectangle about 12 by 3 by 1 1/4 inches. Cut the rectangle in 1/2 then cut the pieces in 1/2 again, giving you 4 (3-inch) squares. Cut the squares in 1/2 on a diagonal to give you the classic triangle shape. Place the scones on your prepared baking sheet and brush the tops with a little heavy cream. Bake for 15 to 20 minutes until beautiful and brown. Let the scones cool a bit before you drizzle on the glaze. In a small saucepan, over low heat, combine juice with the powdered sugar until dissolved. Whisk in the butter and lemon zest if using. Stir constantly until smooth. Drizzle the glaze on top of the scones. Serve and enjoy!