Preheat the oven to 350°F. Line a baking sheet with parchment paper or a silicone baking mat and set aside.

In a large bowl, whisk together the oats, flour, baking powder, baking soda, cinnamon, and salt until evenly combined.

In the bowl of a stand mixer, beat the butter, brown sugar, and vanilla until light and creamy. Add the egg and mix until fully incorporated.

Gradually add the dry ingredients to the wet ingredients, mixing on low speed just until combined. Fold in the dried cranberries and pistachios, being careful not to overmix.

Scoop 1-tablespoon portions of dough onto the prepared baking sheet, spacing them about 2 inches apart. Bake for 8–10 minutes, or until the edges are lightly golden and the centers are just set.

Let the cookies cool on the baking sheet for a few minutes before transferring them to a wire rack to cool completely.