In a large mixing bowl cream together the butter, peanut butter, sugar and brown sugar until fluffy. Use a spatula to scrape the bottom and sides of the bowl occasionally.
Add the eggs and vanilla. Gradually incorporate the flour, salt, baking powder and baking soda. Mix until incorporated into peanut butter mixture. Scrape the bottom and sides of the bowl to be sure everything is mixed well. Add chocolate chips if desired.
Cover and chill the cookie dough in the refrigerator for 2 hours or overnight. Or transfer the cookie dough into a large zip-style freezer bag and refrigerate.
Preheat the oven to 375 degrees F.
Scoop chilled cookie dough into balls, using a small cookie scoop or a tablespoon. If using a tablespoon, roll in your hands to make rounds.
Roll into sugar and place on place evenly on a half sheet pan lined with parchment paper leaving a little bit of space in between each cookie. Use a fork dipped into sugar to make a crisscross pattern on the top of each cookie.
Bake for 15-17 minutes or until the edges are very lightly browned. Turn the sheet pans around half way through baking.
The cookies will look soft, but will set while cooling. Let cool on a sheet pans until set (about 10 minutes) before removing with a spatula to cool completely on a wire baking rack.
Store any remaining cookies in an airtight container for 4-5 days.
Notes
If desired, melt 1 ½ cups of semisweet chocolate chips in a double boiler. After the cookies are cool, spoon on a tablespoon or so to the bottom of each cookie. Press them onto a half sheet pan lined with parchment paper. Cover & refrigerate to set the chocolate.Rotating your baking pans about half way through baking will give you more evenly baked cookies. Rotate baking pans 180-degrees and rotate from top to bottom, and from bottom to top rack.