Preheat oven to 350.

In a medium-sized mixing bowl whisk together the Nutella, eggs, sugar, milk, and vanilla.

Whisk in the flour and mix until smooth and creamy.

Grease a mini brownie pan or a mini cupcake pan with baking spray..

Pour the Nutella mixture into each cavity, about 2/3 full.

Bake for 14 to 15 minutes, or until a toothpick inserted in the middle comes out clean.

Invert onto a cooling rack and let cool.

Dust with powdered sugar and serve.