Preheat the oven to 350 degrees F. Line an 8 or 9-inch square baking dish with parchment paper. Set it aside.
In a large mixing bowl with paddle attachment (to an electric mixer), combine crust ingredients. Turn on low and mix until crumbly. You could skip the mixer and cut them together with a pastry cutter or your hands.
Press crumbs into the bottom of the prepared baking dish. Bake for 15 minutes.
While the crust is baking, make the lemon filling. You can use the same bowl. Combine sugar, flour, baking powder, eggs, lemon zest & juice. Mix until blended.
After 15 minutes, remove crust from oven and immediately pour the lemon mixture over the partially baked crust. Sprinkle 1/2 cup of the coconut over the top.
Return baking pan to the oven for 10 minutes. Add the remaining 1/2 cup coconut over the top and cook an additional 10 minutes.
Cool bars, then chill for 2 hours (or longer). Cut into bars and sprinkle with about 1-2 Tablespoons of powdered sugar. Enjoy.
Notes
You'll need one lemon for this recpe. I don't measure anymore, but it will be about 1 teaspoon of zest and 2 Tablespoons of juice.
Store bars in the refrigerator for up to one week. Or freeze for up to one month.