How to cook
Put 3 whole eggs + 1 yolk (set aside white for later) in a bowl. To them add the sugar, grated lemon rind and stir. Add the oil. Mix with the effervescent yeast. Knead a soft, stretchy dough. A good cozonac requires patience and a very warm room for the dough to rise.
It's going to need 2-3 hours at a room temperature of 81°F (27 °C) to rise well. Once risen, divide it up depending on whether you're making 2 large or several smaller cozonacs. Now comes the tricky part - the kneading.
Grandma used to always say that you have to hit the dough 100 times on the table but I'll leave that to the boldest of you. Vigorous kneading for an extended period gets the job done as well. Shape it into thread or rosettes - you decide.
Smear it with egg yolk and leave it for a time before sprinkling generously with sugar. Bake small cozonacs in a preheated 356°F (180 °C) oven about 35 min. on the middle oven element, with fan off. If baking a large one, bake about 50 min.