Preheat the oven to 350 degrees and line a baking sheet with parchment paper.
Combine the dry ingredients (flour, baking soda, and salt) in a small bowl and set aside.
Using a stand or hand mixer, cream the butter, brown sugar, and granulated sugar. This will take about 2-3 minutes.
Add in the peanut butter, egg, and vanilla. Mix to combine.
Add in the dry ingredients and mix until combined.
Using two tablespoons of sough, roll into a ball and set on the parchment paper. Leaving about 2 inches of space between each ball. You must bake the cookies in batches to avoid overcrowding the pan.
Using a fork, make a cross-hatch pattern once the dough is placed on the baking sheet.
Bake the cookies for 10-12 minutes or until the dough starts to brown on the edges.
Remove cookies from the oven and let cool completely on a wire rack.
Once the cookies are completely cooled, melt the chocolate carefully so it doesn't burn. Drizzle each cookie with the melted chocolate to your liking.