Activate Yeast:
Mix warm milk and yeast with a pinch of sugar. Let sit 5–10 minutes until foamy.
Make Dough:
Add sugar, egg, butter, flour, and salt. Knead until smooth and soft.
First Rise:
Cover and let rise 1–1.5 hours until doubled.
Shape Doughnuts:
Roll dough to 1/2-inch thickness. Cut rounds and place on tray. Let rise 30 minutes.
Fry:
Heat oil to 350°F (175°C). Fry until golden on both sides. Cool completely.
Make Pastry Cream:
Heat milk. Whisk sugar, yolks, and cornstarch. Slowly add milk, then cook until thick. Stir in butter and vanilla. Cool.
Make Glaze:
Heat cream and pour over chocolate chips. Stir until smooth, add butter.
Fill Doughnuts:
Pipe pastry cream into each doughnut.
Glaze:
Dip tops into chocolate glaze. Let set.
Serve:
Enjoy fresh for best flavor and texture!