Preheat oven to 325°F. Line a baking sheet with parchment paper or a silicone baking mat.
Cream both of the sugars with the room temperature butter in a stand mixer fitted with a paddle attachment or with a hand mixer. Slowly add the eggs in, one at a time. Followed by the vanilla.
Sift together the flour, baking soda and powder, and salt in a separate bowl. Add dry ingredients to the wet in batches until incorporated.
Fold in the oats and pecans with a spatula, mixing until fully dispersed. Wrap the bowl with plastic and place in the refrigerator for 30 minutes to allow the dough to firm up.
You can either roll the cookies into logs and wrap in parchment to freeze or use a small cookie or ice cream scoop and place on a baking sheet about 1 inch apart. These cookies will spread and become very flat and lacy looking.
Bake for 8-11 minutes or until lightly golden, set and lacy.