In the bowl of a stand mixer fitted with the paddle attachment, add the butter and sugars. Cream them together on medium-high speed until the mixture is light and fluffy, about 3 minutes.

Next, add the peanut butter and mix on medium speed for one minute, making sure to scrape down the sides of the bowl.

Add the egg and vanilla extract, mixing until well combined.

In a separate bowl, whisk together the flour, baking soda, baking powder, and salt.

Gradually add the dry ingredients to the wet ingredients, mixing on low speed until just combined. It’s okay if a few streaks of flour remain—do not overmix.

Remove the bowl from the mixer and use a large spatula to fold in the chocolate chunks (or chips) and pretzel bits.

Using a large 2-ounce cookie scoop, portion out rounds of dough onto a parchment-lined baking sheet. Chill the dough for two hours or overnight.

Once the dough is chilled, preheat the oven to 350°F (175°C). Line two baking sheets with parchment paper. Transfer the chilled dough to the prepared pans, leaving 2 inches between each cookie, as they will spread during baking.

Bake for 11 to 12 minutes, stopping halfway through to remove the pan from the oven and firmly tap it on the countertop to help flatten the cookies. Rotate the pan and continue baking until the edges are set, while the centers of the cookies remain puffy and look slightly underbaked.

Remove the pan from the oven and let the cookies cool on the baking sheet for 10 minutes before transferring them to a wire rack. If desired, sprinkle with flaky sea salt before serving.