1. Preheat oven to 350°F. Spray and line 9 inch baking pan with foil, allowing foil to hang over side. Spray foil. Combine graham cracker crumbs, granulated sugar, and melted butter and press into bottom of pan. Bake 5-7 minutes, until golden, allow to cool.
2. Prepare brownie mix for cake like brownies. Fold in chopped peanuts. Pour over crust and bake 30-35 minutes- until just set. Cool completely.
3. With electric mixer, beat cream cheese until smooth. Add peanut butter and confectioners' sugar until just blended (batter will be lumpy). Add milk, beat lightly. In separate bowl, whip 1 cup of the cream and fold gently into the peanut butter mixture. Spread mousse evenly over cooled brownies. Refrigerate 1 hr.
4. Heat remaining 1/2 cup cream over medium heat until just boiling. Remove from heat and add corn syrup and chocolate chips. Cover and let stand 5 minutes. Pour and spread over the cooled mousse. Refrigerate at least another hour.