01 -
Combine instant yeast with warm water or milk in a small bowl. Let stand for 10 minutes until foamy.
02 -
In the bowl of a stand mixer, blend flour, sugar, and salt. Pour in the yeast mixture, mixing on low speed until combined.
03 -
Add eggs one at a time, fully mixing each before adding the next.
04 -
Add butter, lemon zest, and vanilla extract if using. Knead until the dough is smooth and elastic, about 8–10 minutes.
05 -
Cover the dough and let it proof in the refrigerator overnight or at room temperature until doubled in volume (1–2 hours).
06 -
Turn out the risen dough. Divide into 12 even pieces and roll into balls. Place on a parchment-lined baking tray.
07 -
Cover shaped dough balls with a towel and proof at room temperature until doubled in size, about 45–60 minutes.
08 -
Heat oil to 175°C in a deep fryer or heavy pot. Fry doughnuts in batches for 2 minutes per side, turning for even browning.
09 -
Transfer fried doughnuts to a paper towel-lined tray to drain excess oil.
10 -
Heat milk until steaming but not boiling. In a separate bowl, whisk egg yolks, sugar, and cornstarch until smooth.
11 -
Gradually whisk hot milk into egg mixture, then return to saucepan. Cook over medium heat, stirring constantly, until thick.
12 -
Remove from heat. Whisk in butter, vanilla, and rum or brandy if using. Cool to room temperature, then transfer to a piping bag.
13 -
Pierce each cooled doughnut with a piping tip and inject with prepared pastry cream.
14 -
Sprinkle doughnut tops with an even layer of sugar. Caramelize with a kitchen torch or dip in wet caramel (heat sugar with a small amount of water until deep golden).
15 -
Allow caramel to harden. Optionally garnish with chopped nuts, spices, or cocoa powder. Serve immediately for optimal texture.