Make the batter

• Whisk the eggs with the milk in a bowl.
• Add the Nutella and whisk until smooth.
• Sift in the flour and mix until just combined.

Cook the brownie

• Pour the batter into a lightly greased pan over low heat.
• Cover and cook gently until set and a toothpick comes out clean.

Serve

• Let it cool slightly, then cut into portions.