Preheat oven to 350°F and line two baking sheets with parchment paper.
Place the slices of butter in a saucepan set over medium heat.
6 tablespoons salted butter
Allow to melt and then constantly stir until bubbling and brown, about 5 minutes.
Remove from the heat as soon as it browns and transfer it to a small bowl. Allow the butter to come to room temperature (it will solidify slightly).
Once the butter has cooled, add it to the bowl of a stand mixer fitted with the paddle attachment. Add in the sugar and beat until it is well combined.
½ cup granulated sugar
Add in the peanut butter, egg, and vanilla and mix to combine.
½ cup creamy peanut butter, 1 large egg, 1 teaspoon pure vanilla extract
Whisk together the flour and baking soda and powder in another small mixing bowl, then beat into the butter mixture on low speed.
½ cup all-purpose flour, ¼ teaspoon baking soda, ¼ teaspoon baking powder
Transfer the dough to the fridge to chill for exactly 30 minutes.
Once chilled, scoop out the dough and shape into 1-inch balls.
Using a fork, flatten the cookies and make a crosswise pattern. Make sure to place the cookies at least 2-3 inches apart on the baking sheet because they spread!
Bake until the edges begin to turn golden brown, about 15 minutes.
Transfer to a wire rack to cool.