Preheat the oven to 355°F. Line an 8x11-inch baking sheet with parchment paper.
Sift the flours into a medium bowl. Add all dry ingredients and mix to combine with a spoon or an eggbeater.
In the bowl of a stand mixer, add the egg, coconut oil, honey, and orange peel. Run a mixer for 2 minutes, until all the ingredients are well combined. Add dry ingredients and mix until a dough forms, about 3 minutes. The dough should be smooth and a bit wet, but you should be able to handle it with your hands. Add a little bit of gluten-free oat flour if the dough is too loose. Cover with plastic in place in the fridge for an hour.
Transfer the dough onto a lightly floured work surface and roll it ½-inch thick, flouring as needed. Cut out the heart shapes with a cookie cutter and transfer the cookies to the baking tray lined with parchment paper. Bake for 15 minutes. Remove from the oven and cool completely on the baking sheet.
Decorate with powdered sugar, as desired. Gingerbread hearts can be stored in an airtight container for up to a week.
*You can replace these flours with equal parts gluten-free all-purpose flour blend of your choice.