Prepare the cookie dough and let it rest in the fridge as per recipe
In the meantime peel, core and dice the apple
Add it to a pan with cinnamon, sugar, grated lemon zest and butter/ghee and cook for 10 minutes over low/medium heat, stirring occasionally
Pre-heat oven at 320F/160C and line a cookie sheet with parchment paper
Roll out the cookie dough on a floured surface (use white rice flour), 3-4 millimeters thick, and cut out disks using a cookie cutter or simply a glass/cup
(Roll out remaining dough and cut out cookie disks until all the dough is used up)
Move half the dough disks on the cookie sheet and add a spoonful of apple filling on every disk
Place the other disks on the cookie bases, lightly press the edges together with your fingers and then with a fork
Bake for 13-15 minutes on middle oven rack, until the cookies are lightly gold on top
Let the cookies cool down completely before removing them from the cookie sheet
Dust with powdered sugar, if desired.
Stored in an airtight container and at a cool temperature, these cookies keep nice and flaky for several days.