Preheat the oven to 350F then line an 8x8 inch baking pan with parchment paper and set aside.
In a large bowl combine the butter, oil, and brown sugar together and microwave in 30-second increments stirring in between every time. We want the butter to be melted and the mixture to look glossy so this can take up to 1 minute and 30 seconds.
6 tablespoon butter, 2 tablespoon vegetable oil, ½ cup brown sugar
Once the mixture has slightly cooled, whisk in the eggs one at a time. Continue whisking until the mixture is light and fluffy.
2 egg
Add in the Nutella and the vanilla extract and mix to combine. Fold in the flour, cocoa powder, and salt and mix just until the flour mixture disappears. Mix in the chocolate chips now if using.
1 teaspoon vanilla extract, 1 cup Nutella, ⅔ cup flour, 2 tablespoon cocoa powder, ½ cup chocolate chips, ¼ teaspoon salt
Pour the brownie batter into the prepared baking pan and top with dollops of ¼ cup of Nutella. Using a knife or a wooden skewer, swirl the Nutella into the batter.
¼ cup Nutella
Bake the brownies in the preheated oven for 25-30 minutes or until a toothpick inserted in the center comes out with a few moist crumbs on it. Let the brownie cool completely before slicing into it, top with sea salt and enjoy!
sea salt