Preheat oven to 350F and line a baking sheet with parchment paper.
In a medium bowl, whisk together flour, baking powder, baking soda, salt and cinnamon.
In a large bowl, cream together the butter and the sugars. Beat in the egg, followed by the applesauce and the vanilla extract. Working by hand, stir in the flour mixture and the oats until just combined and no streaks of flour remain. Stir in the chocolate chips.
Drop tablespoonfuls of the dough onto the prepared baking sheet, flattening each cookie slightly. Bake for about 10-12 minute Cookies will be light brown at the edges when done.
Let cool on sheet for 3 or 4 minutes, then transfer to a wire rack to cool completely.