My Hanukkah Jelly Donut recipe (Sufganiyah) makes powdered sugar-covered, homemade jelly donuts that are delicious any time of the year, but classically made and eaten during Hanukkah!
In the bowl of a stand mixer fitted with a dough hook (or large mixing bowl), combine water, yeast, sugar, flour, vegetable oil, eggs, vanilla extract, and salt blend with the mixer on low for 15 minutes (or knead by hand but the mixture will be very sticky).
Place the kneaded dough in a large, oiled bowl, cover with plastic wrap and a tea towel and leave in a warm place to rise until it has doubled in size, roughly 2 hours.
Once the dough has doubled in size, line a baking sheet with parchment, and dust the parchment and a work surface with flour.
Turn the dough out on the floured surface, gently pat the dough to a 1/2-inch (13mm) thickness, and using a 2 ½ inch (6cm) round cutter dipped in flour, cut as many circles as you can and place on your prepared baking sheet. You can gather and re-roll any scraps.
Dust the cut circles of dough with a little more flour, cover with a dry tea towel or plastic wrap, and let rise again for about an hour.
When the doughnuts have risen, heat oil 2-3 inches (5-8cm) deep in a sturdy pot fitted with a candy thermometer if you have one.
Line a baking sheet with paper towels, set a wire rack on top of the paper towels, and place all this near the stove.
Heat the oil over a medium heat (or has reached 325°F/165°C). Fry 3-4 doughnuts at a time for 2-3 minutes, or until it is golden in color. Carefully flip and fry the other side for another minute or two, until golden.
Lift the doughnuts out of the oil and let drain on the prepared wire rack. Repeat with the remaining doughnuts.
Once the doughnuts are cool, poke a hole in the side or top of the doughnut with a straw or skewer.
Place the strained jam into a piping bag fitted with a small plain tip. Squeeze a small amount of jam into each doughnut and then dust the doughnuts with powdered sugar.
These doughnuts are best the day they are made. Store any leftovers in an airtight container at room temperature for up to 2 days.