prepare brownie mix according to package directions, using the 13x9x2-inch pan option. cool compleatly on a wire rack. when cooled smash 3/4 of the browines in the bottom of the 9x3 inch springform pan forming an even crust. spred with the hot fudge ice cream topping, now crumble the remaining browines and set aside.
in a large mixing bowel, combine cream cheese and peanut butter. beat with an electric mixer on medium speed for until just combined. add sweetened condensed milk, beat until just combined. in a medium bowel beat whipping cream until soft peaks form. add powdered sugar. beat until stiff peaks form. reserve 1/2 the whipped cream mixture and fold the other 1/2 into the cream cheese mixture.
spread one-half of the cream cheese mixture over the hot fudge topping in pan. sprinkle the rest of brownie over the cream cheese mixture. spread the rest of the cream cheese mixture over the browine. top with reserved whipped cream mixture. put the chopped peanut butter cups ontop. drizzle chocolate syrup over cheesecake. cover and chill for 4 to 24 hours.