- Prepare the Brioche Dough:
- In a small bowl, dissolve the active dry yeast in warm water and let it sit for about 5 minutes, or until foamy.
- In the bowl of a stand mixer fitted with the dough hook attachment, combine the flour, sugar, and salt. Add the yeast mixture and eggs, and mix on low speed until the dough comes together.
- Add the softened butter, a few pieces at a time, and continue to mix until the dough is smooth and elastic, about 5-7 minutes.
- Transfer the dough to a greased bowl, cover with plastic wrap, and let it rise in a warm place for about 1-2 hours, or until doubled in size.
- Make the Pastry Cream:
- In a saucepan, heat the milk over medium heat until it just begins to simmer.
- In a separate bowl, whisk together the sugar, cornstarch, and egg yolks until smooth and pale.
- Gradually pour the hot milk into the egg mixture, whisking constantly.
- Return the mixture to the saucepan and cook over medium heat, whisking constantly, until thickened.
- Remove from heat and stir in the vanilla extract. Transfer the pastry cream to a bowl and cover with plastic wrap, pressing the plastic wrap directly onto the surface of the cream to prevent a skin from forming. Chill in the refrigerator until cold.
- Shape and Fry the Donuts:
- Punch down the risen dough and turn it out onto a lightly floured surface. Roll out the dough to about 1/2 inch thickness.
- Using a round cookie cutter or drinking glass, cut out circles of dough. Place a small dollop of chilled pastry cream in the center of each circle of dough.
- Fold the dough over the pastry cream to enclose it completely, pinching the edges to seal.
- Heat vegetable oil in a deep fryer or large pot to 350°F (175°C). Fry the filled donuts in batches until golden brown on both sides, about 2-3 minutes per side. Drain on paper towels.
- Serve:
- Dust the warm donuts with powdered sugar before serving.
These mini pastry cream-filled brioche donuts are best enjoyed warm and fresh, with a cup of coffee or tea. Enjoy the delicious combination of buttery brioche and creamy pastry cream in every bite!