Preheat oven to 350° F. Prepare a donut baking pan by lightly spraying with cooking spray. Set aside.
In a medium bowl, combine gluten free flour, guar or xanthan gum (do not use if in blend), baking powder, salt, cinnamon and nutmeg.
In another small bowl, combine melted butter, brown sugar, eggs and vanilla until eggs are completely combined. Add apple cider and stir. Pour this mixture into the flour mixture. Stir until flour is combined and most lumps are gone. Your batter should be similar to the consistency of cake batter, semi-runny.
Using a spoon, carefully pour batter into each donut cavity, filling to almost the top. Bake for 13-15 minutes, the tops will be slightly golden brown. Remove from oven and allow to cool for a few minutes before removing from the pan. Once removed, place on a cooling rack. Allow the donuts to cool slightly before topping.