Preheat your oven to 350°F (175°C) to ensure even baking.
In a large mixing bowl, cream the softened butter, white sugar, and brown sugar using an electric mixer on medium speed until light and fluffy, about 2-3 minutes.
Add the peanut butter and vanilla extract to the creamed mixture and mix until well combined.
Crack the egg into the mixture and beat until fully incorporated.
In a separate bowl, whisk together the all-purpose flour, baking soda, and salt. Gradually add this dry mixture to the wet ingredients, mixing until just combined.
Gently fold in the rolled oats and peanut butter and chocolate swirl chips, being careful not to overmix.
Use a cookie scoop to drop rounded tablespoons of dough onto a parchment-lined baking sheet, leaving space between cookies for spreading.
Bake in the preheated oven for 10-12 minutes, until edges are lightly golden. Centers may look soft but will firm as they cool.
Remove cookies from the oven and let cool on the baking sheet for about 5 minutes before transferring to a wire rack to cool completely. Enjoy!