Preheat oven to 350° F. Line baking sheets with silicone baking mats or parchment paper.
In a large mixing bowl, combine peanut butter, unsalted butter, light brown sugar, and granulated sugar. Using an electric mixer, cream on medium speed until well combined.
Add egg and vanilla extract and continue to mix until well combined.
Add all-purpose flour, baking soda, baking powder, and salt. Mix until the dry ingredients are combined with the wet ingredients. Do not overmix. Scrape the bowl to ensure all the ingredients are well combined.
Using a medium cookie scoop (1 ½ tbsp), portion the peanut butter cookie dough.
Roll the dough balls into smooth spheres and place onto the silicone baking mat, allowing space for spreading.
Using a fork or potato masher, create a hashtag on the top of each cookie. Sprinkle with additional sugar if desired.
Bake the cookies for approximately 12 minutes.
Remove the baking sheet from the oven and allow the cookies to cool on the pan for 2-3 minutes. Transfer the cookies to a wire rack to cool completely.