Preheat the oven to 350°F (175°C).

Cream together the unsalted butter, light brown sugar, and granulated sugar in a large bowl using a mixer for 2-3 minutes until smooth and fluffy.

Incorporate the creamy peanut butter and beat until fully combined.

Add in the egg and vanilla extract, mixing well until smooth.

Whisk together the all-purpose flour, baking soda, baking powder, and kosher salt in a separate bowl.

Gradually mix the dry ingredients into the wet mixture, stirring just until combined.

Fold in the chopped chocolate and mini pretzel pieces.

Scoop tablespoon-sized portions onto a baking sheet lined with parchment paper, spacing them about 2 inches apart.

Flatten each cookie slightly and add more chocolate and pretzel pieces on top if desired.

Bake for 10-12 minutes or until golden brown.

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