Sprinkle the yeast and sugar over the water and set aside for 5 minutes. Measure the flour into a mixing bowl. Once the yeast foams, pour the water into the center of the flour and stir until you have a smooth batter. Cover the bowl with a damp cloth and let the batter rise for an hour.

Combine sugar, water and lemon juice in a heavy saucepan. Bring to a boil, reduce the heat to medium, and simmer for about 10 minutes, until the syrup is thick enough to coat a cold metal spoon. Turn off the heat and stir in the rosewater or orange flower water. Transfer the syrup to a metal bowl and refrigerate until the ataif are ready to be doused.

Lightly oil a heavy frying pan or griddle, and turn up the heat to high, until the pan is thoroughly heated. Reduce the heat to medium to maintain a steady temperature. Pour 1 tablespoon of batter into the pan and fry the pancake until small bubbles form on the surface. Remove the pancake to a platter and continue until the batter is all used up.

Heat 2" of oil in a pot suitable for deep frying. Spoon a tablespoon of ricotta cheese onto the uncooked center of each cake; or fill with a tablespoon of nut filling made by combining ground nuts, sugar and cinnamon. Fold the pancake in half and pinch gently around the edges so that they will stick together. Deep fry each pancake until it becomes golden, about 2 or 3 minutes. Remove with a slotted spoon to lint-free absorbent towels. Dip the hot pancakes into the cold syrup, remove with a slotted spoon, and arrange on a serving platter. Sprinkle with chopped nuts.

Ataif may be enjoyed either hot or cold.