In a mixing bowl combine the dry ingredients; flour, salt, baking powder, and cornstarch. Set aside.
Place softened butter, sugar and brown sugar in a large mixing bowl.
Beat together on high speed until light and fluffy, about 3 minutes. Scrape down sides of the bowl as needed.
Add eggs, one at a time.
Add peanut butter and vanilla. Beat until combined.
Reduce speed to low and slowly add dry ingredients until well combined with the wet ingredients.
Stir in peanut butter chips, and peanuts.
Refrigerate dough for 1 hour.
Preheat oven to 350℉.
Line cookie sheets with either parchment paper or a silpat liner.
Using a large cookie scoop form dough into 2½ oz sized balls.
Roll each ball in sugar to coat.
Place balls of dough on prepared cookie sheets, lined with either parchment paper or a silpat liner.
Gently press dough balls into thick flattened discs using a fork to make a criss-cross pattern.
Sprinkle each cookie with a little additional sugar if desired.
Bake cookies for 15-18 minutes. Centers will still be very soft.
Remove from oven and allow cookies to cool for 10 minutes before carefully transferring them onto a rack to cool completely.
Store covered, at room temperature, for up to 3 days.