Preheat your oven to 350°F (175°C) and line a baking sheet with parchment paper.

In a medium bowl, whisk together the all-purpose flour, baking powder, and fine sea salt.

In a large mixing bowl, combine the melted unsalted butter, granulated sugar, light brown sugar, creamy peanut butter, egg, and vanilla extract. Mix until smooth and creamy.

Gradually add the dry mixture into the wet ingredients and mix on low speed until just combined.

Scoop generous tablespoons of dough, roll into balls, and coat in granulated sugar.

Place the dough balls on the baking sheet, spaced about 1.5 to 2 inches apart.

Using a fork, press down on each dough ball to create crosshatch patterns.

Bake for 12 to 14 minutes until edges are golden brown and centers are soft.

Allow the cookies to cool on the baking sheet for 5-10 minutes before transferring to a wire rack.