Combine yeast, water, and sugar:
In a small bowl, combine yeast, warm water, and 1 teaspoon sugar. Set aside until foamy, about 10 minutes.
Add eggs, yeast mixture, and butter to flour to form dough:
Place flour in a large bowl. Make a well in the center; add eggs, yeast mixture, 1/4 cup sugar, butter, nutmeg, and salt. Using a wooden spoon, stir until a sticky dough forms.
Knead dough:
On a well-floured work surface, knead until dough is smooth, soft, and bounces back when poked with a finger, about 8 minutes (add more flour, if necessary).
Place in bowl and set aside to rise:
Place in an oiled bowl; cover with plastic wrap. Set in a warm place to rise until doubled, 1 to 1 1/2 hours.
Roll dough and cut out rounds:
On a lightly floured work surface, roll dough to 1/4-inch thickness. Using a 2 1/2-inch-round cutter or drinking glass, cut 20 rounds. Cover with plastic wrap; let rise 15 minutes.
Heat oil and fry donuts:
In medium saucepan over medium heat, heat oil until a deep-frying thermometer registers 370°F. Using a slotted spoon, carefully slip 4 rounds into oil. Fry until golden, about 40 seconds. Turn doughnuts over; fry until golden on other side, another 40 seconds.
Roll doughnuts in sugar:
Using a slotted spoon, transfer to a paper-towel-lined baking sheet. Roll in sugar while warm. Fry all dough, and roll in sugar.
Fill with jam:
Fill a pastry bag fitted with a #4 tip with jam. Using a wooden skewer or toothpick, make a hole in the side of each doughnut. Fit the pastry tip into a hole, pipe about 2 teaspoons jam into doughnut. Repeat with remaining doughnuts.
Storage
Homemade doughnuts like sufganiyot are best enjoyed the day they are made. If you have any leftovers, store them in an airtight container at room temperature and eat within a day. Don’t store them in direct sunlight as this would cause them to sweat and become soggy.
Frequently Asked Questions
What's the difference between paczki and sufganiyot?
In Poland, jelly doughnuts are called paczki which means flower buds. Traditionally, they were fried in lard which sets them apart from sufganiyot, which are fried in oil.
What is the difference between a yeast doughnut and a regular doughnut?
The difference between a yeast doughnut and other types of doughnuts is how they are leavened. Yeast doughnuts are made with yeast, whereas baked or cake doughnuts use a chemical leavener, such as baking powder or baking soda.
