Start by activating the yeast. In a bowl, combine the warm milk, sugar, and yeast. Let it sit for about 5–10 minutes until frothy. This little fermentation party gets the yeast riled up! In a large mixing bowl, beat the eggs, melted butter, and salt together. Once the yeast mixture bubbles up, pour it in. Blend these together. Next, gradually add the flour, stirring until a dough forms. Mix until the dough pulls away from the sides. It should feel slightly sticky but smooth.

Flour your countertop and turn the dough out. Knead it for about 8-10 minutes. You want it smooth and elastic. If it sticks too much, sprinkle a bit of flour, but don't overdo it!

Place your dough in a greased bowl, cover it with a clean kitchen towel, and let it rise in a warm spot. This will take about an hour or until it doubles in size. Patience is key here.

While the dough rises, let's whip up that creamy filling. In a saucepan, combine the whole milk, heavy cream, salt, and sugar. Heat it until it’s steaming but not boiling. In another bowl, whisk the egg yolks and cake flour together. Temper the yolk mixture by whisking in a little of the hot milk mixture to prevent the eggs from scrambling.  Gradually add the egg mix back to the saucepan, stirring constantly until it thickens. It should coat the back of a spoon. Stir in the vanilla extract, and then transfer it to a bowl. Cover it with plastic wrap touching the surface to prevent a skin from forming.

Once the dough has risen, punch it down to remove the air. Roll it out on a floured surface about ½ inch thick. Use a round cutter to cut out the doughnuts, and place them on parchment paper sprinkled with flour. Re-roll the scraps to make more doughnuts.

Cover the cut doughnuts with a towel again. Let them rise for another 30-45 minutes until puffed.

Heat the canola oil in a deep pot or frying pan to 360°F (182°C). Fry the doughnuts in batches, being careful not to overcrowd the pan. Each side should take about 2-3 minutes until golden. Use a slotted spoon to transfer them to a wire rack set over paper towels to drain excess oil.

As soon as the doughnuts cool slightly, roll them in granulated sugar. This gives that wonderful touch.

Using a piping bag fitted with a long, wide tip, fill each doughnut with the prepared pastry cream. Insert the tip into the side and squeeze gently until you feel resistance.