Preheat oven to 350°F and line two baking sheets with parchment paper.
In a medium bowl, combine flour, oats, baking powder, baking soda, and salt. Set aside.
In a large bowl, combine butter and sugars until well mixed. Add egg and vanilla extract and mix until blended. Add flour mixture and mix until just combined, then add pecans and chocolate chips and mix well.
Portion onto prepared baking sheets, about 2 Tbsp per cookie, leaving 2-inch between each. Bake until the edges are golden-brown, about 12 minutes. Let cool on baking sheet for 5 minutes then remove to a wire rack to cool completely.