Position two racks in the upper and lower thirds of the oven and preheat to 350°F. Line two baking sheets with parchment paper.

In a medium bowl, whisk together the oats, flour, baking powder, baking soda and salt.

In the bowl of an electric mixer, beat together the butter and brown sugar on medium speed until creamy, about 3 minutes. Scrape down the sides of the bowl with a rubber spatula, then add the egg and vanilla and beat again until smooth, about 30 seconds.

Add the flour and oatmeal mixture and mix on low speed until just combined; add the pecans and raisins and mix again until just combined. Do not over-mix.

Drop the dough into 1½-tablespoon mounds about 2 inches apart onto the prepared baking sheets. Bake for 11 to 13 minutes, rotating the pans from top to bottom and front to back halfway through, or until the edges are slightly golden but the centers are still pale. Let the cookies cool on the baking sheets for a few minutes, then either slide the papers off the pans onto cooling racks or transfer the cookies with a spatula. Once cool, store the cookies in an air-tight container.

Freezer-Friendly Instructions: The cookie dough can be frozen for up to 3 months. Scoop into balls, freeze on a baking sheet until firm, then transfer to a sealable bag, pressing out as much air as possible. Bake directly from frozen, adding 1 to 2 minutes to the baking time. The baked cookies can also be frozen. Once cooled completely, store in an airtight container with parchment or foil between layers. Let them come to room temperature before serving.