Custard Filled Donut

Instructions

1. Prepare the dough
   In a large bowl, combine flour, sugar, yeast, and salt. In a separate bowl, whisk together warm milk, eggs, melted butter, and vanilla. Add the wet ingredients to the dry ingredients and mix until a shaggy dough forms. Knead on a floured surface for 8-10 minutes until smooth and elastic. Place in a greased bowl, cover, and let rise in a warm place for 1-2 hours until doubled in size.
2. Make the custard filling
   In a medium saucepan, heat 1½ cups of milk until steaming but not boiling. Meanwhile, in a bowl, whisk together sugar, cornstarch, egg yolks, and remaining ½ cup milk until smooth. Slowly pour half the hot milk into the egg mixture while whisking constantly. Pour the mixture back into the saucepan and cook over medium heat, stirring constantly, until thickened (about 2 minutes after it starts to bubble). Remove from heat, stir in vanilla and butter until smooth. Transfer to a bowl, cover with plastic wrap directly on the surface, and refrigerate until chilled.
3. Shape the donuts
   Punch down the risen dough and turn out onto a lightly floured surface. Roll to ½-inch thickness. Using a 3-inch round cutter, cut out circles. Place on parchment-lined baking sheets, leaving 2 inches between each donut. Cover loosely and let rise for 30-45 minutes until puffy.
4. Fry the donuts
   Heat oil in a deep, heavy-bottomed pot to 350°F. Carefully lower 2-3 donuts into the hot oil and fry until golden brown, about 2 minutes per side. Remove with a slotted spoon and drain on paper towels. Repeat with remaining donuts, making sure the oil temperature stays consistent.
5. Fill with custard
   Once donuts are completely cool, use a small knife to create a small hole in the side of each donut. Transfer the chilled custard to a piping bag fitted with a long filling tip. Insert the tip into each donut and gently squeeze to fill with custard until you feel slight resistance.
6. Finish and serve
   If desired, dust the filled donuts with powdered sugar or dip the tops in chocolate glaze. Allow any glaze to set before serving. Donuts are best enjoyed the same day they're made.