Preheat your oven to 350 and line a cookie sheet with parchment paper (or lightly grease a whoopie pie pan).
Beat butter and sugar in the bowl of an electric mixer until light and fluffy. It will probably take a couple of minutes.
Add the peanut butter and beat on lower speed until incorporated.
Add the eggs, one at the time, beating until combined. Scrape the sides and bottom of the bowl.
Mix in the vanilla extract.
While on low speed, add flour, baking soda and salt, mix until all incorporated.
Fold in the chocolate chips and caramel bits.
Scoop out the cookie dough with a cookie scoop, shape (into a ball and then slightly flatten) and place about 2 inches apart (or in the center of a whoopie pan cup).