Step 1: Prepare Doughnuts

1. In a bowl, combine warm milk, sugar, and yeast. Let sit for 5 minutes until bubbly.
2. Add egg and melted butter, whisking to combine.
3. Gradually add flour and salt, kneading until smooth and slightly sticky dough forms.
4. Place dough in a greased bowl, cover, and let rise for 1 hour until doubled in size.

Step 2: Shape & Rise Doughnuts

5. Roll dough on a floured surface to ½-inch thickness.
6. Cut doughnuts using a 3-inch round cutter. (Don’t cut holes; these will be filled.)
7. Transfer doughnuts onto a lightly floured baking sheet, cover, and let rise again for 30 minutes.

Step 3: Fry Doughnuts

8. Heat vegetable oil in a deep pot or fryer to 350°F (175°C).
9. Fry doughnuts in small batches (2-3 at a time) for about 1-2 minutes per side until golden brown.
10. Drain doughnuts on paper towels and let cool completely.

Step 4: Make Vanilla Custard Filling

11. In a saucepan, heat milk over medium until steaming (do not boil).
12. In a bowl, whisk together egg yolks, sugar, cornstarch, and salt until smooth.
13. Gradually whisk the hot milk into egg mixture.
14. Return mixture to saucepan, cook over medium heat, whisking continuously, until thickened (about 3-4 minutes).
15. Remove from heat, stir in butter and vanilla extract until smooth. Let custard cool completely, covered with plastic wrap touching surface to avoid skin formation.

Step 5: Fill Doughnuts

16. Fill a piping bag fitted with a round tip with custard.
17. Using a skewer, create a hole in the side of each doughnut.
18. Pipe custard generously into each doughnut.

Step 6: Chocolate Ganache & Finish

19. In a bowl, heat heavy cream until steaming. Pour over chocolate chips.
20. Let sit for 2 minutes, then stir until smooth and glossy.
21. Dip tops of doughnuts into chocolate ganache, allowing excess to drip off.

Step 7: Serve & Enjoy!

22. Allow chocolate to set briefly, then serve fresh and enjoy!