With a pastry robot:

• the lightly beaten egg, the melted butter, the sugar and the mixture of milk and yeast.
• Beat the dough vigorously for 20 minutes,
• until it becomes soft and elastic
• By hand: In a bowl, combine the butter, egg,
• sugar and a pinch of salt.
• Add milk with baking powder and flour.
• Mix well and transfer everything to a lightly floured work surface.
• Keep kneading with your hands until you get a smooth, elastic dough.
• Put the dough in a bowl covered with a cloth and let rise until it has doubled in volume.
• My advice is to leave it in a turned off oven with the light on.
• After the rising time, roll out the dough into a rectangle
• half a centimeter thick on a lightly floured work surface.
• Using a cookie cutter, cut out 6cm discs.
• Place the donuts on a baking sheet and put a square of baking paper under each donut.
• This will help you pick them up without touching them with your hands
• once they are up, to dip them in the hot oil.
• Cover the donuts with a cloth and let rise another 1 hour.
• Meanwhile, prepare the Italian diplomat cream
• by mixing the pastry cream with the liquid cream whipped with the two tablespoons of icing sugar.
• Pour the oil into a saucepan with high edges and,
• once very hot, plunge the donuts (no more than 2 at a time)
• so as not to lower the temperature of the oil.
• Let rise and brown for 5 to 6 minutes per donut.
• To give a sweet touch to these delicious donuts
• Put the Italian diplomate cream in a piping bag and fill the donuts.