Preheat oven to 350 degrees Fahrenheit and line an 8x8 baking pan with parchment paper.
Beat the eggs on high for 7-10 minutes (until they roughly triple in size).
Heat the Nutella by microwaving for 60 seconds, stirring and repeating until very warm.
Slowly add the warm Nutella to the eggs, beating until thoroughly combined.
Pour the batter into the prepared pan and bake for 30 to 35 minutes (until a toothpick inserted in center comes out almost clean).
Cool completely before cutting.
Optionally, dust with powdered sugar.