For the batter, place the egg yolks in a food processor for 5 seconds, then add the cream cheese and beat until smooth
Add the brown sugar and vanilla and process for several minutes,or until the batter is very smooth
Add the sour cream, then beat the eggwhites and fold into the cheese mixture, set aside
To make crust, soften butter and combine with graham cracker crumbs
Mix until fully blended, e.g. they will form a ball when squeezed in your hand or by a spoon
Put the crust into the sides and bottom of a springform pan about 22 cm in diameter
Spread a generous layer of chips on the bottom of the pan, and then pour the batter into the pan
Add another generous layer of chips to the top of the cake.
Place the filled pan into the preheated oven
Baking time will vary from about 30 minutes to 2 hours
TIPS:
Cooking time depends on whether you want a soft, gooey New York style cheesecake(shorter) to a fluffy soufflelike cheesecake (longer). The
longer you cook it, the fluffier it gets.
When the cake starts to rise like a souffle, start checking to see if it is done. It will just about double in volume, and should not flow over the sides of the pan. If the cake shimmers like Jello when shaken, it is done. Alternatively, if a knife inserted comes out clean, the cake is overcooked.The knife should be very lightly coated with batter.
