Line a 2 ltr freezer safe bowl with cling film, making sure to leave over hangs.
Slice store bought Swiss rolls into 1/2 inch pieces and line the bowl with the same.
To layer the ice cream, first, pour in a few dollops of the caramel ice cream, then place a small bowl covered with cling wrap in the center, then fill the gaps with the remaining caramel ice cream.Tap the bowl a few times in between so that the ice cream can seep in between the Swiss rolls.
Cover the cake properly with the cling film and freeze till the first layer is almost set. It will take 3 - 4 hours.
Remove the bowl and the cling film and fill the center with the chocolate ice cream and spread evenly. If the ice cream does not fill the bowl, trim of the extra cake on the sides. Cover and freeze again.(best kept overnight)
Thaw the cake for at least 5 min before trying to take it out of the mold. Invert in onto a serving platter or plate. Let it thaw again for 10-15 min so that it becomes sliceable.
Serve as is or top it with some hot fudge sauce. Enjoy :)!!
Notes
Recipe for Hot Fudge sauce: Add 1 can(397 gm) sweetened condensed milk and 1 cup semi-sweet chocolate chips to a saucepan over medium heat and stir constantly until the chocolate is completely melted. Remove from heat and add 2 tbsp unsalted butter. Store hot fudge sauce in a glass jar and use white hot. (To reheat: Place the jar in the microwave and heat in 20-second increments, stirring in between each, until melted and smooth.