A friend passed on a tip to me the other day. Grace lives down the street from me and has two grown daughters with Celiac, as well as several sisters and nieces (and nephews? - I can't remember :))
Her sister had mentioned that she puts a teaspoon of apple cider vinegar in her gluten free baking (muffins, cakes, waffles, pancakes, etc) and it results in a lighter, better texture! I have yet to try it, but I am eager to see if it makes a difference. I imagine it adds some acidity that makes the baking powder more effective (???) or something like that.
Worth a try, I say!