In a large bowl, mix flour with sugar. Dissolve the fresh yeast in little warm milk and add to the flour mixture. Add eggs and rest of the milk, sour cream, lemon zest and oil and mix everything together. Knead until smooth.
Cover it and let it sit for about 1 hour at room temperature, to let the dough rise until nearly doubled in size.
Shape the rolls.
Punch the dough down, knead, and split into 23-25 equal pieces. Roll each piece of dough into a thin rope, about 30 cm (12 inches) long . You can use oil if the dough is sticky.
Grease the bottom of a barbeque stick and wrap dough rope around it. Beat the egg and brush each roll. Sprinkle sugar (and cinnamon if using) all over the roll surface and roast it slowly over the fire until golden brown.
When it's done, let it cool for a minute then remove slowly from the stick and serve with vanilla cream filling, fresh strawberries on top and sprinkle with strawberry topping.