For the blintzes:
Put the flour in a bowl and make a well in the center. Add eggs, salt, and half the milk, blending them into the flour until smooth. Whisk in the remaining milk or water. The batter should be as thick as heavy cream. (Alternately you can mix the batter in a food processor or blender.) Refrigerate for 1 hour (or longer if more convenient). Melt the butter, then let it cool to lukewarm and whisk it into the batter. Heat an 8-inch frying pan. Brush lightly with oil. Add 3 tablespoons batter to the edge of the pan and swirl to coat the bottom. Loosen the edges with a spatula. Cook until the undersurface is firm and lightly golden. Make blintzes until all the batter is used, stacking them with wax paper between each one. Keep them warm with a towel. Makes about 14.
¾ cup all purpose flour 4 eggs, beaten ½ teaspoon salt 1¼ cups milk or water or more as needed 2 tablespoons butter oil for brushing the pan
For the Cheese filling:
Mash the cheeses. Beat them with egg yolks, sugar and cinnamon until mixture is smooth and thoroughly blended. Spoon 2–3 tablespoons filling on browned side of each blintz near one edge. Fold the edges of the blintz over the filling, then roll up so filling is enclosed. The blintzes can be baked or fried. To bake, preheat the oven to 425º F. Arrange the blintzes in one layer in a shallow, buttered baking dish. Dot each one with two small pieces of butter. Bake for about 15 minutes, or until heated through. To fry, heat the butter in a skillet. Add blintzes seam side down. Fry over low heat for 3–5 minutes. Don't let them burn. Serve hot with sugar or a fruit sauce of your choice.
2 cups cottage cheese 8 ounces cream cheese, softened 2 egg yolks 2-4 tablespoons sugar, or to taste ¼ teaspoon cinnamon 3-4 tablespoons butter for frying