Unroll a sheet of puff pastry on a flat surface and allow it to thaw until chilled, firm and pliable (about 15-20 min.) Keep an eye on it because you don't want it to over thaw and become too soft/breakable.
Use the top of a mason jar, drinking glass or biscuit cutter to cut the dough into 12 circles.
Stack 3 of the circles on top of each other and use your hands or a rolling pin to gently press them together and seal the edges to form a thicker piece of dough. Be careful not to flatten the dough too much, just seal the circles together to create one thick piece of dough, so it doesn't separate when baking!
Use a small knife to cut a hole out of the center of the dough. Cinch the edges around the hole to make sure the layers don't separate. You can keep the small pieces and air-fry the "cronut holes" if you want.
Air fry the dough at 360 degrees for 15-20 minutes, until the cronuts are golden brown and flaky. You can also bake at 375 for 20-25 minutes, or follow the instructioins on the puff pastry box. NOTE: If you have a convection option on your oven, use that to mimic an air fryer!