Beat egg and peanut butter together and add to dry mixture.
Add apples and walnuts and stir until well combined.
Mold into ball-like patties by the 1/4 cup and cook in greased skillet over medium-low heat until bottom is solid and crispy, then flip and do the other side.
Notes
Batter is very wet and crumbly. Pack together each ball as hard as you can, then gently flatten just a tiny bit and carefully place into skillet.Patties will fall apart if squished too thin. If one starts breaking when added to skillet, push it back together or enjoy it as apple oat hash.