Makes one 7" square pan (9 pieces).
A note about substitutions: You might try substituting pea protein powder for the rice protein powder, if you like. But because each type of protein powder has a distinct flavor and texture when baked, I wouldn't use all whey or all vegan protein.
Almond meal can be made by pulsing almonds in a food processor. Sift out the large pieces and pulse again. Be careful not to overprocess, as this will give you almond butter.