Combine "crumbs" (graham cracker or cookies), butter and 1/4 cup sugar. Pack into bottom of springform pan. Bake at 300 degrees for 10 minutes. Gently mix cream cheese and eggs. Beat after adding eggs individually. Slowly add 1 cup sugar and vanilla. Pour into pan. Bake 60 minutes. Allow to cool for 10 minutes. Then combine sour cream, 6 tablespoons sugar and 1 1/2 teaspoons vanilla. Top with mixture. Bake at 300 degrees for 15 minutes longer. Allow to cool slowly at room temperature and then refrigerate. Remove springform pan sides.