Heat milk; stir in the fresh yeast in a bowl.

Whisk the egg and egg yolk.

Place flour, granulated sugar, scraped vanilla seeds from bean or vanilla extract and salt on a wooden cutting board.

With spoon make a hole in center of dry ingredients, carefully pour the milk-and-egg mixture into it.

Knead the ingredients together until a smooth dough is formed. Add softened butter and grated lemon zest and knead until fully incorporated.

Place the dough in a bowl and cover with plastic wrap; let rise for 2 hours.

Roll dough in portions between your palms to form 10 balls.

Place balls on a baking sheet covered with parchment paper. When they’ve doubled in size, fry in oil that’s been heated to 350°F.

Remove the doughnuts from the oil and place on paper towels. Let cool for a few minutes.

Using a piping bag, fill each doughnut with 1 tbsp of Nutella^® hazelnut spread.

Cut a star out of cardboard or construction paper and use it as a stencil to decorate the doughnuts, sprinkling confectioners’ sugar on each one.