1. Preheat oven to 350 degrees F (175 degrees C). In a medium bowl, combine wafer crumbs with the melted margarine. Mix well. Press onto the bottom and half-way up the side of 9 inch springform pan. Bake for 10 minutes in preheated oven. Allow to cool.
2. Increase oven temperature to 400 degrees F (200 degrees C). In a saucepan over low heat, melt the caramels together with the chocolate chips and evaporated milk stir until smooth and pour into crust. Break candy bars into small pieces. Sprinkle over the caramel layer.
3. Beat cream cheese until smooth. Add sugar and flour; beat until smooth. Add eggs, then yolks, one at a time. Blend in heavy cream and vanilla. Pour over caramel and toffee layers. Wrap outside of pan with foil.
4. Set in a large pan that has been filled with 1 inch of hot water. Bake at 400 degrees F (200 degrees C) for 15 minutes; reduce oven to 225 degrees F (110 degrees C) and bake 1 hour. Remove from water. Cool to room temperature, then chill overnight in the refrigerator. Top with 3 more Heath Bar candy bars that have been chopped.
TIPS from others:
I used a whole 250g box of vanilla wafers for the crust and exactly 50 caramels for the sauce. And as per reviewers suggestions, 1)I used a larger (9 1/2 inch) springform pan. 2)I used 3 1/2 skor bars instead of 3 and mixed it in the cheesecake batter rather than under it. (I still used pieces from 3 bars for the top though) 3)I put 3/4 of the sauce on the crust and used the other 1/4 for drizzling over the top and sides of the cake. 4)I used a thermometer to get the internal temperature between 160 and 165 degrees and it took 1 hour and 45 minutes at 225 degrees rather than the 1 hour listed in the recipe. It came out perfect in every way and everyone was so impressed they were taking pictures of it. Thanks to Nancy and the reviewers for making this my favorite cheesecake ever.