In a small bowl, dissolve the yeast and sugar in warm water. Let it sit for about 5 minutes until the mixture becomes frothy.
In a large mixing bowl, combine the flour and salt. Make a well in the center and pour in the yeast mixture. Mix well until a sticky dough forms.
Gradually add more warm water, a little at a time, until the dough becomes soft and pliable. Knead the dough for about 5-7 minutes until it becomes smooth and elastic.
Cover the dough with a clean kitchen towel and let it rise in a warm place for about 1-2 hours, or until it doubles in size.
Once the dough has risen, punch it down to release the air. Divide the dough into small portions and shape them into round balls. Place the dough balls on a floured surface and cover them with a kitchen towel. Let them rest for about 15-20 minutes.
In a large frying pan, heat vegetable oil to medium-high heat. Gently flatten each dough ball and make a small hole in the center using your thumb. Carefully drop the doughnuts into the hot oil and fry them until they turn golden brown on both sides.
Once the donuts are cooked, remove them from the oil and place them on a paper towel-lined plate to drain excess oil.
Serve the Sfenj Moroccan Donuts warm and enjoy!