• Preheat oven to 350 degrees fahrenheit (176 degrees celsius). Grease an 8x8 inch baking pan with non-stick baking spray and line with parchment paper.
• In a microwave-safe bowl, microwave Nutella on high for about 1 minute, stirring every 15 seconds or so, until soft and creamy.
• Using an electric mixer (or stand mixer), whisk eggs until pale and creamy (around 7-8 minutes). Add Nutella to eggs and whisk on low speed until well combined (around 2 minutes). 
• Pour mixture into prepared baking pan and bake for 25 minutes or until the edges start to pull away from the sides of the pan. Let cool before slicing into bars.

optional third ingredient:

• sprinkle mini milk or dark chocolate chips on top of bars after taking out of the oven!