Ingredients

For the Cookies:
1/2 cup (1 stick) unsalted butter, softened
1 cup brown sugar, packed
1 large egg
1 teaspoon vanilla extract
1 1/4 cups uncooked old-fashioned oats
1 cup all-purpose flour
1/2 teaspoon baking powder
1/2 teaspoon baking soda
1/2 teaspoons salt
1 teaspoon ground cinnamon
1/4 teaspoon ground nutmeg
1/2 cup chopped pecans

For the Filling:
3 tablespoons unsalted butter, at room temperature
1/2 cup smooth peanut butter
1 cup powdered sugar
3-4 tablespoons milk

Directions

Place racks in the center and upper third of the oven and preheat oven to 350 degrees F. Line two baking sheets with parchment paper and set aside.

Beat the sugar and butter in the bowl of a stand mixer fitted with a paddle attachment. Beat until creamy, about 3 to 4 minutes. Add egg and beat on medium speed for about 1 minute. Add the vanilla extract and beat until blended.

In a medium bowl, whisk together the oats, flour, baking powder, baking soda, spices, and salt. Add the dry ingredients to the butter and egg mixture slowly beating on low speed until just incorporated. Stir in the pecans last.

The cookies will be small, so portion about 1 heaping teaspoon of cookie dough into your hand. Roll into a ball and place on the prepared cookie sheet. Keep cookies about 1 1/2-inch apart on the baking sheet. If the cookie dough begins to stick to your hands as you’re making dough balls, rinse your hands and portion the dough with just slightly damp hands.

Bake for 10 to 13 minutes or until they’ve reached your desired doneness. I like mine a little underdone and cook them for 10 minutes. Allow to cool on the cookie sheet for 5 minutes before transferring to a wire rack to cool completely.

To prepare the filling, place butter, peanut butter, and powdered sugar in the bowl of an electric stand mixer fitted with the paddle attachment. Beat on medium speed, drizzling in vanilla extract. Scrape down the bowl as necessary. Add milk one tablespoon at a time until you’ve reached your desired consistency. The filling should be easily spreadable.

When cookies are completely cool, flip over and spread half of the cookie bottoms with peanut butter filling. Top with a similar size cookie. Wrap individually and store in the refrigerator. Cookies are best served slightly chilled. Cookies last, wrapped in the fridge, for about 5 days.