Add the cocoa powder and blend until the dough is smooth and even. If the color is too light, add more cocoa powder to achieve the classic dark color.

Meanwhile, line a small baking sheet with parchment paper and drop spoonfuls of Nutella onto it. Place them in the freezer for 1 hour.

Roll out the dough between 2 sheets of parchment paper using a rolling pin.

Use a round cookie cutter or a narrow glass to cut out circles.

Place the circles on a parchment-lined baking sheet.

Put a frozen Nutella portion in the center of each circle.

Cover with another circle and seal the edges well all around.

Bake in a preheated oven at 350°F (180°C) for 10 minutes.

Let cool and enjoy.