Line a 2 ltr freezer safe bowl with cling film, making sure to leave over hangs.
Slice the store-bought jam Swiss rolls into less than an inch pieces and line the bowl with the same.
Squeeze some strawberry sauce into the gaps using a piping bag or spoon. (this step is optional).
For the homemade ice cream, beat the heavy cream to soft peaks. Add in vanilla extract, and sweetened condensed milk and give it a mix.
Pour the ice cream mixture into the Swiss roll mold alternating with dollops of strawberry sauce. Create swirls using a butter knife.
Cover the cake properly with the over-hanging cling film and freeze till set. (best kept overnight)
Thaw the cake for at least 10 min before trying to take it out of the mold. Invert in onto a serving platter or plate. Then let it thaw again for 10-15 min so that it becomes sliceable.
Slice and Enjoy :)
Notes
You can also use store-bought vanilla ice cream instead of making it.