Preheat oven to 350 and spay a 9x13 baking pan with baking spray.
Using a large bowl, beat together the butter and sugar until light and fluffy.
Beat in the eggs 1 at a time until combined.
Beat in the pumpkin and vanilla until combined.
In a medium bowl, whisk together the flour, pumpkin pie spice, baking soda, and salt until combined.
Gradually beat the dry ingredients into the wet.
Spread half of the batter into the pan.
Using a small spoon, drop dollops of Nutella onto the batter.
Using a butterknife, swirl the Nutella into the batter.
Spread the remaining batter onto the bottom half.
Drop more dollops of Nutella onto the top of the batter.
Gently swirl the Nutella into the batter.
Place bars into the oven and bake for 25-35 minutes or until a toothpick comes out clean.
Allow to cool completely before enjoying!