01 -
Heat oven to 325°F.
02 -
Grease 9-inch springform pan.
03 -
Mix graham crumbs, brown sugar, vanilla, and melted butter.
04 -
Press into pan bottom and sides.
05 -
Spread chocolate chips and marshmallows over crust.
06 -
Beat cream cheese until fluffy, mix in cornstarch and sugar, add eggs one at a time, mix in sour cream, vanilla, and heavy cream.
07 -
Pour over crust.
08 -
Place in water bath, bake 90-95 minutes.
09 -
Turn off oven, open door halfway, rest 10 minutes in oven, rest 10 minutes on counter, loosen edges with knife, cool 1 hour.
10 -
Turn on broiler, add warm fudge and marshmallows, broil 30-35 seconds until toasted.
11 -
Cool completely, chill 4 hours.