Angel Food Cake (Gluten Free!)

For my mom's birthday, I told her I would make her an angel food cake (one of her favorites). Now granted, her birthday was over 2 months ago. Of course I thought, if I'm going to go through making one from scratch (I'll admit, I used to be an avid boxed angel food cake mix person) I might as well gluten free so I can try it, too :)  Besides that, I knew my friend Erika (who has to eat gluten free) loves angel food cake and if I could try out a recipe to pass onto her, the better! Here is the original recipe, I did make a few alterations due to the ingredients I had on-hand and also noted are the changes I would make the next time.

1 1/2 c egg whites (It took 9 eggs for me this time. Save your yolks and freeze them in an ice cube tray, then pop into freezer bag. I'm saving mine to make creme brulee.)
3/4 c plus 1/2 c organic cane sugar, divided (I would definitely use less next time, it was a bit sweet)
1/4 c arrowroot powder
1/4 c white rice flour
1/4 c quinoa flour
1/4 c potato starch
1 1/2 tsp cream of tartar
3/4 tsp salt
1 tsp vanilla extract (I will use a bit more next time)
1/2 tsp almond extract (This was not in the original recipe, but I recently tried some almond cookies made by my friend Jen and they had a distinct angel food cake flavor so I think by adding a smidge of almond extract it will complete the flavor of the cake!)

Separate eggs and let white come to room temperature. Sift 3/4 c sugar, arrowroot, flours and starch together twice.
Preheat oven to 350 and get out ungreased tube pan.
Add cream of tartar, salt, vanilla and almond to egg whites and beat on medium until soft peaks form. Gradually add remaining sugar (decrease amount next time) beating on high until stiff peaks form. 
Gently fold in flour mixture, about 1/2 c at a time. Cut through batter with a knife to remove air pockets.
Bake on lowest rack (I did not do this but will next time) for 45-50 minutes or until lightly browned and top appears dry.
Invert pan above plate and allow to cool about 1 hour (I could not wait this long!)
Run a knife between cake and pan to loosen and place on plate.Cut and enjoy!