Preheat your oven to 350 degrees F. This is crucial for getting those cookies just right!
Line a large baking sheet with parchment paper. This prevents the cookies from sticking and makes cleanup easier.
In a medium bowl, whisk together 1 1/4 cups all-purpose flour, 3/4 cup old fashioned rolled oats, 1 teaspoon baking soda, and ¼ teaspoon salt. This mixture forms the dry base of your cookies.
In the bowl of an electric mixer, combine 1/2 cup softened butter, ½ cup all natural creamy peanut butter, and 1 cup packed brown sugar. Mix on medium-low until well combined. You should see a smooth, creamy consistency.
Switch the mixer to low speed and add in 1 egg, 1 teaspoon vanilla extract, 1/2 tablespoon honey, and 1/2 tablespoon sour cream. Beat for about a minute until everything is well blended and smooth.
Slowly add the dry ingredients to the wet mixture, increasing the mixer speed to medium-low. Mix until just combined. If you're using mini chocolate chips, now’s the time to fold them in!
Using a small cookie scoop, grab a tablespoonful of dough and roll it into a ball. It’s important to keep the size small since the cookies will expand while baking.
Place the dough balls on the lined cookie sheet, leaving about 2 inches of space between each ball.
Bake for 10 to 12 minutes or until the edges are lightly golden brown. A slightly underbaked cookie is best for that chewy texture.
Allow the cookies to cool on the cookie sheet for 5 to 10 minutes before transferring them to a wire rack to cool completely. This helps them firm up nicely.
To prepare the peanut butter filling, add 1/4 cup softened butter and ¼ cup creamy peanut butter to the mixer, whipping on high until light and fluffy.
Gradually add in 1 cup powdered sugar, 1 teaspoon vanilla, and 1 tablespoon milk. Beat until creamy. If you desire a creamier texture, add a splash more of milk.
Take one cookie, spread a generous spoonful of the filling on top, and top it with another cookie, gently pressing down. Repeat this process until all cookies are sandwiched.
For the best texture, let the assembled cookies sit at room temperature for an hour before enjoying. This helps the filling firm up perfectly.
