I tried substituting the almond flour with oat flour (I used the same measurements) and the cookies turned out great! (therealfoodrds.com)
I did make a mistake and poured milk into oat mixture instead of egg mixture by mistake so it all got mixed together in bowl before it went into the pan - still yummy. (epicurious.com)
In a pinch, you can use 2 1/2 cups of oat flour instead of the ground oats in this recipe. (kingarthurflour.com)