Preheat oven to 350℉.
Melt chocolate chips by microwaving for 30 seconds, then giving them a stir, then repeat microwaving for 15 seconds, then stirring, a few more times until the chocolate is smooth.
While the melted chocolate is still warm, stir together the melted chocolate with the Nutella.
Using a handheld or stand mixer, cream together the butter and both sugars for about three minutes.
Add the eggs and vanilla and mix again.
Next, add the chocolate/Nutella and mix just until smooth.
In a separate bowl, stir together the flour and salt. Finally, add this to the wet ingredients and again mix just until smooth. The consistency of the batter will be quite thick, but no worries, this is to be expected.
Using a rubber spatula, spread the batter into a greased 9″ x 9″ baking pan.
Bake for 35-40 minutes or until a toothpick inserted in the center comes out mostly clean. Also, give the brownie pan a shake. If there’s any jiggle, give them just a few more minutes and then they’ll be ready.