Custard Donuts

Yeast mixture:

1. In a large bowl, whisk the warm milk with the room-temperature egg, once combined add the instant yeast. Whisk fully until dissolved.

Donut dough:

1. Then, add sugar, flour, and salt to the yeast mixture. Use a spatula to mix until combined and after that knead with your hands until all flour has been incorporated.
2. Next, add the softened butter and work it in with your hands until the dough is smooth.
3. Transfer the dough onto a flat, lightly floured surface and knead for two to three minutes.
4. After that, transfer the sticky dough ball into a large lightly oiled bowl and cover it with plastic wrap. Place it in a warm place and let it rise for a few hours until it is about two to three times its starting size.

Pastry cream:

1. In the meantime, in a small bowl whisk the egg yolks, sugar, and salt until combined.
2. In a small saucepan, heat the butter and milk over medium heat until the butter is fully melted.
3. Next, slowly and while stirring constantly, pour the milk mixture into the egg yolk mixture. Do this a little at a time until all the milk has been combined.
4. After that, stir in the vanilla extract.
5. Stir in the flour until fully combined.
6. Next, transfer the mixture back into the saucepan and cook while stirring on low heat until it reaches 220 degrees F measured with a candy thermometer. Make sure to whisk constantly until it is thick.
7. Remove it from the heat, scoop it into a mixing bowl, cover it with plastic wrap, right on top of the cream (so it touches it), and let it chill in the fridge for a few hours.

Shape the donuts:

1. In the meantime, punch the dough and then transfer it to a lightly floured surface. Fold it a few times and divide it into eight equal pieces.
2. Shape each piece into a ball and place it on a baking sheet covered in parchment paper. Repeat with the remaining pieces. Make sure they are not too close to each other on the baking sheet. Cover them with plastic wrap and let them rest for 30 to 40 minutes.

Deep frying donuts:

1. Place a large, deep pan with about 1 1/2 - 2 inches of oil over low-medium heat. Bring the oil to 350 degrees F. Add a few donuts at a time and fry them for 1-2 minutes on one side, or until golden brown. Flip and repeat.
2. Remove them from the oil with a slotted spoon and place them on a wire rack to cool.

Fill:

1. After the donuts have cool completely, poke a hole, using a long rounded object, like a chopstick. Place a bowl with about one cup of sugar next to you. Then roll them in sugar until covered on both sides.
2. Transfer the pastry cream into a pipping bag, cut a small hole at the end and fill the donuts with custard until you have just a little ball of custard on the surface.