Preheat oven to 350 degrees F (175 degrees C). Crush zwieback into crumbs. In a medium bowl, combine zwieback crumbs, 1/2 cup sugar, cinnamon and melted margarine. Mix well and press into the bottom and sides of a 9 inch springform pan.
In a large bowl, cream cottage cheese and 1 1/4 cup sugar until smooth. Beat in eggs one at a time. Beat in the flour and salt. Mix in cream and vanilla.
Pour batter into crust and bake in preheated oven for 1 hour. Cool completely before removing from pan.