1
Preheat oven to 350 degrees. Stir together oats, flour, baking soda, baking powder, and salt in a medium bowl; set aside.
2
Put sugars, butter, and peanut butter in the bowl of an electric mixer fitted with the paddle attachment. Mix on medium speed until pale and fluffy, about 5 minutes. Mix in eggs and vanilla.
3
Reduce speed to low. Add oat mixture, and mix until just combined. Mix in peanuts and chocolate chips.
4
Using a 1 1/2-inch ice cream scoop, drop balls of dough 2 inches apart on baking sheets lined with parchment paper.
5
Bake cookies, rotating sheets halfway through, until golden brown and just set, 13 to 15 minutes. Let cool on sheets on wire racks 5 minutes. Transfer cookies to wire racks to cool completely. Cookies can be stored in airtight containers at room temperature up to 2 days.