The recipe calls for 1/4 cup of flour. She suggested soy flour, I think I used brown rice flour. I wouldn't use a nut or bean flour since they already have a denser base with the nuts in them. If you aren't worried about gluten, an oat or whole wheat flour would be fine.
Also, I used almond meal, rather than ground almonds, because I had it on hand. The recipe calls for 1 cup of finely ground almonds, but if you are using almond meal I would recommend a heaping 3/4 cup or so rather than doing a 1-1 conversion.
I would guess that one muffin has between 12-15 grams of protein and very few grams of sugar, making for a good post-workout snack or protein fix for vegetarians.