Add oats to food processor and pulse into coarse flour.
In large mixing bowl, whisk together oats, vanilla, and cinnamon.
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.