1stick (113 g) plus 3 tbsp (42 g)softened butter, separated
1½cups (375 g)creamy or chunky peanut butter (not natural)
3cups (375 g)powdered sugar
112-ounce bag (340 g)semi-sweet chocolate chips
Place the one stick of butter and the peanut butter in a large bowl and beat on medium high until well combined and creamy.
Slowly add the powdered sugar on low speed until combined. Mix on medium high until well combined. It will look like large crumbs.
Remove the "dough" from the bowl and press it into a parchment or waxed paper lined 9 x 13-inch dish, pushing to the corners until the bottom is completely covered.
Melt the chocolate chips with the remaining 3 tbsp of butter in a small saucepan (or in the microwave) until all the chips have been melted and the mixture is thick and smooth. Dollop spoonfuls of the chocolate mixture all over the peanut butter mixture and spread it to the corners using an offset spatula.
Chill until set, about 30 minutes. Remove from refrigerator, cut into squares, and serve. Store at cool room temperature( or in the refrigerator) for up to one week (if they last that long)!
*Peanut butter bars can be frozen. Cut into 2-inch squares, flash freeze (place in one layer on parchment-lined baking sheet and freeze until firm), then wrap with plastic wrap or foil before putting in a large gallon-size bag. Remove as many bars as desired and let thaw in one layer, unwrapped, at room temperature, about 30 minutes to an hour, depending on ambient temperature.