FOR CRUST AND TOPPING:
PREHEAT oven to 350° F. Lightly grease 13 x 9-inch baking pan.
COMBINE flour, nuts, brown sugar and butter in medium bowl; reserve 1 cup mixture for topping. Press remaining mixture onto bottom of prepared baking pan. Bake for 10 to 12 minutes or just until light golden brown.
BEAT cream cheese, sugar and vanilla extract in small mixer bowl until smooth. Beat in eggs. Gradually beat in evaporated milk.
MICROWAVE morsels in medium, uncovered, microwave-safe bowl on HIGH (100%) power for 1 minute; STIR. The morsels may retain some of their original shape. If necessary, microwave at additional 10 to 15-second intervals, stirring just until morsels are melted. Beat into cream cheese mixture. Pour over hot crust. Sprinkle with reserved topping mixture.
BAKE for 25 to 35 minutes or until center is set. Cool in pan to room temperature. Refrigerate for about 1 hour.
NOTE: Store in refrigerator after serving.