Preheat oven to 350. Line a 8x8 baking pan with parchment paper. I like to spray non stick and then place the parchment paper so it sticks well to the pan.
In a large mixing bowl, add your flour, sugar and cocoa powder. Combine well.
Add in your melted butter and mix well.
Stir in your eggs one by one and your vanilla. Mix well, about 1 minute.
Fold in your chocolate chips with a spatula and combine well.
Transfer half of your batter to the baking pan. Spread evenly.
Spread your nutella on top of the batter and spread evenly using the back of a spoon or offset spatula.
Add in the other half of your brownie mixture and spread evenly.
Bake for 30 minutes
Once they are done baking, let them cool for atleast 15 minutes otherwise they will fall apart!