First, make the dough for the crust. Combine the softened butter, egg yolk, powdered sugar and coconut extract in a bowl and stir them together well. Then stir in the flour until you get a dough forming. Gently bring it together into a firm ball with clean hands in the bowl and set it in the refrigerator to chill for 30 minutes. When time is up, turn the dough out onto a well floured, clean surface and roll it out into a large, really thin disc. Get out an 8 inch springform pan and spray it really well with cooking spray. Press the disc into the pan. Don’t worry if it falls apart, just patch it up. Let the dough chill again for another 30 minutes in the pan.