In a medium bowl, mix cream cheese, 1/4 cup sugar, 1 egg and 1 teaspoon vanilla until smooth, set aside. In a large saucepan, melt margarine and chocolate over low heat. Remove from heat and cool slightly. Beat remaining eggs and mix with chocolate. Add remaining sugar and vanilla and mix well. Gradually stir in flour. Fold in crushed cookies. Spread evenly in a greased 9 x 13" baking pan. Spoon cream cheese mixture over chocolate mixture. Run a knife through mixtures to marble. Bake at 350 degrees for 30 minutes or until edges begin to pull away from the sides of the pan and center is set. Cool completely and cut into 2" squares. Makes 24 squares.