Preheat oven to 350 degrees F (175 degrees C). Place butter in a 9x13-inch baking dish.
Place baking dish in the oven until butter is melted and evenly coats the bottom of the dish, 3 to 5 minutes.
Arrange cheese blintzes seam-side down in 4 rows of 3 blintzes each. Turn blintzes over twice, ensuring they are coated with melted butter.
Beat sour cream, eggs, orange juice, sugar, vanilla extract, and cinnamon vigorously in a bowl until well-blended. Pour mixture evenly over blintzes. Give the dish a shake to ensure blintzes are evenly coated.
Bake in the preheated oven until a knife inserted into the center comes out clean and top is browned, 45 to 50 minutes.