Preheat the oven to 190°C (375°F) and line a baking tray with parchment paper.

In a stand mixer fitted with the paddle attachment, beat together the butter, peanut butter, dark brown sugar, vanilla extract, and salt until creamy.

Add the egg and beat again until fully incorporated.

Scrape down the sides of the bowl. Add the flour, baking powder, and baking soda, then mix until a soft dough forms. Fold in most of the chocolate, reserving some for topping.

Roll the dough into large balls and slightly flatten. Place on the prepared baking tray. Top each with a few pretzel pieces and the reserved chocolate. Sprinkle with coarse salt.

Bake for 8–12 minutes, or until the edges are golden and the centers are soft but set.

Let cool for a few minutes on the tray before transferring to a wire rack. Serve warm for the best gooey texture.