Crust:
Combine flour, sugar and salt. Cut in butter. Add egg and mix well.
Pat the dough evenly into the bottom of a 9x13-inch pan. Set aside.
Filling:
Put the cottage cheese in a strainer. Stir and press the cheese to remove as much moisture as possible.
Cream cottage cheese and about ¼ cup of the milk in a blender. Drop in pieces of cream cheese and blend until very smooth. Add more of the remaing milk as necessary to blend. Pour into mixing bowl.
Add cornstarch and mix.
Add eggs, one at a time mixing well after each.
Add sugar, lemon, butter, vanilla, and mix well.
Add remaining milk and mix. Pour mixture over the crust.
Bake at 350 degrees for 50 minutes. Cool in pan. Sprinkle with cinnamon and refrigerate overnight before serving.