Preheat oven to 350 degrees.
Combine butter, peanut butter, sugars, egg, and vanilla. Mix until well combined.
Combine flour, baking soda and salt in a large measuring cup or bowl. Slowly stir in to the peanut butter mixture.
Drop spoonfuls of Nutella on top of the dough and swirl it through the dough with a butter knife.
Chill the dough for 15 minutes in the refrigerator.
Roll into balls by hand.
Place the balls of dough on a parchment lined cookie sheet.
Use a fork to lightly press the balls down and make a criss-cross pattern.
Bake until the edges are very lightly browned, about 7 to 10 minutes.
Allow to cool for 2 minutes on the cookie sheet before transferring to a cooling rack.