For the dough
1. Add the yeast, milk and sugar to a bowl and mix slightly with a spoon.
2. Place the flour, butter, salt, yolk and egg in the mixer bowl. With the hook attachment, knead on medium speed for 2-3 minutes until a soft dough is formed.
3. Add the yeast mixture and knead at medium to high speed for about 10-12 minutes until we have a smooth dough.
4. Transfer to an oiled bowl and cover with cling film.
5. Let it rise at a temperature of 28-29 degrees Celsius for 1.5 hours.
6. When it rises, remove the film and press with your fist right in the center of the dough to release the air.
7. We transfer our dough to the counter and give it a spherical shape.
8. With the rolling pin, roll out our dough evenly to a thickness of 2 centimeters.
9. Prepare a tray with greaseproof paper.
10. With a round hoop, cut the donuts and transfer them to the pan.
11. Cover with a towel and let them rise for about 45 minutes to 1 hour.
12. When they are ready, use scissors to cut the parchment paper around the perimeter of each donut.
13. Heat the seed oil to 175 degrees Celsius.
14. Carefully transfer each donut to the hot oil with the parchment paper.
15. Remove the parchment paper and fry for about 45 seconds on each side or until golden brown.
16. Immediately after removing them from the oil, transfer them to the sugar and sprinkle them well.
17. Leave them aside to cool.
18. Pierce the donuts on one side and fill with the pastry cream and blueberry sauce.

For the cream
1. In a saucepan, add the milk, half the amount of sugar and the vanilla extract and heat.
2. In another bowl, put the egg yolks, the cornmeal and the remaining sugar and mix with a whisk. As soon as our milk is heated, we take a small amount with a spoon and transfer it to the bowl with the yolks and mix with the whisk.
3. Immediately after, transfer to the saucepan, lower the heat and continue stirring until our cream thickens.
4. Put our cream in a bowl and cover with cling film. The membrane must be in contact with our cream.
5. When it cools, mix again with the wire and transfer to a pastry bag with a round tip.

For the raspberry sauce
1. In a small saucepan, add the frozen blueberries, sugar and lemon juice.
2. Place on medium heat and stir frequently until the sauce thickens.
3. Set aside to cool and transfer to a pastry bag.