Make the dough. Combine flour, yeast, sugar, salt, and water in a bowl. Mix to combine until the dough is homogenous.
Rise. Cover with a clean towel and set aside to rise until the dough doubles in size, about an hour.
Shape the donuts. Heat the oil in a pan to medium high. Rub your hands with oil before grabbing a 2 inch ball of dough and using your fingers to poke a hole through the center and form a donut shape.
Fry the sfenj. Gently add each donut to the oil, shaping & frying a few at a time and making sure not to overcrowd the pan. Fry until golden brown all around, flipping occasionally to prevent them from burning.
Toss in sugar or honey (optional). Lay sfinj to dry on a paper towel and enjoy as is or top with a sprinkle with sugar or drizzle of honey.