Grease 9" springform pan; sprinkle with graham cracker crumbs, tilting pan to coat the sides.
Into a large bowl, mash cottage cheese through sieve; add cream cheese. Beat on high setting with electric mixer until well blended. Beat in sugar, then 2 eggs.
Reduce speed to slow. Beat in cornstarch, lemon juice and vanilla, then margarine or butter and sour cream until smooth.
Pour into prepared pan. Bake in 325 deg F oven for 70 minutes or until firm around the edge. Turn oven off. Let cake stand in oven for 2 hours. Take out and chill. Remove side of pan. If desired, cover with Strawberry glaze. Freezes well.
STRAWBERRY GLAZE: Mix cornstarch, water and light corn syrup until smooth. Add strawberries. Bring to a boil for 1 minute. Strain. Stir in lemon juice and, if desired, a drop of red food coloring. Cool slightly, then cover top with glaze.