Preheat oven to 375℉.Line two baking sheets with parchment paper. Silicone mats can also be use. Unwrap candies and set aside.
Cream together the butter and sugars in a stand mixer or with a hand held mixer until fluffy. About 2 minutes total. Add the egg and mix in to combine. Add peanut butter and vanilla and mix until smooth and creamy.
In a bowl whisk together the flour, salt and soda and add to wet mixture. Mix this in JUST until combined. It is important to not over mix.
Using a medium cookie scoop, scoop dough into balls. This is about 1 ½ Tablespoons of dough. I like to roll the sides of the cookie ball in the extra sugar. This just gives it a classic look. Leaving about 2 inches between scoops.Bake at 375℉ for about 10 minutes. They should just be starting to crack and appear done on the sides. It is super important not to over bake!
Remove from oven and immediately press unwrapped candy into center of cookie.
Allow to cool for 2-5 minutes then remove to wire rack to cool completely.