Preheat oven to 375 F.
Mix together the flax and water. Set aside.
Whisk together the milk, oil, vanilla, molasses, and apple sauce in a small bowl. Set aside. In separate larger bowl whisk together the sugar, baking powder, baking soda, GF flour, almond flour, and salt.
Fold the wet ingredients into the dry and mix until no dry clumps remain. Fold in the soaked flax last. Because this recipe is gluten free you won't need to worry about over-mixing. However, if you are using all-purpose flour make sure you stop mixing before it seems like you should stop. You don't want to develop gluten which will make your donuts tough and not cakey.
Spray donut pans with oil or brush with oil.
Fill each mold to just below the top. Approximately 3-4 Tbl per mold.
Bake for 16-18 minutes. Let rest in pan for 2 minutes then remove from pan and let cool on wire rack.
Read notes for topping options.