Line a baking sheet with parchment paper, and set aside.
In a large bowl, combine all cookie dough ingredients starting with the dry then adding in the butter or coconut oil, and maple syrup. Stir with a spatula until fully combined to form your dough.
On another piece of parchment paper, use a rolling pin to roll your dough about a quarter inch thick.
Use a 2.5 inch heart cutter to make 20-22 hearts. Then, use a mini .5 inch heart cutter and cut out a smaller heart “window” in half of the cookies.
Bake for 12 to 14 minutes. Check on them at the 10 minute mark to make sure your cookies aren’t browning too much — remove from the oven and fully cool on a rack.
When cookies are cool, spread about ½ tsp of the chocolate hazelnut frosting on each solid heart cookie, then top with the “window” heart cookies to form sandwiches.
