In a medium bowl, whisk together oats, flour, baking powder , salt, and cinnamon. Set aside.
In a large bowl, whisk together butter, brown sugar, and sugar until smooth. Whisk in eggs and vanilla followed by applesauce. Stir in dry ingredients. Add apple bits andwalnuts andstir to combine .cover dough with plastic wrap( I do in bowl as its very wet) let rest for one hour.
Adjust oven rack to middle position and preheat oven to 350 .line two baking sheets with parchment paper. Use a cookie scoop or tablespoon to drop tablespoons of dough onto prepared baking sheets. Bake until cookies are golden at the edge bake about 15 minutes.
Let cookies cool completely on pan .they are sticky but will dry out as they cool.store in an air tight container, layering with wax paper.