Arrange Swiss roll slices on the bottom a tart dish.
Drain the guava and reserve the syrup.
Process guavas in a food processor.
Heat 125 ml of the guava syrup together with 20 ml custard powder to thicken.
Add the guava pulp and allow to cool.
Spoon cooled mixture over the cake slices.
Beat the cheese, condensed milk and lemon juice together.
Beat well until mixture thickens.
Carefully spoon mixture over guava layer.
Refrigerate until set and serve topped with guava slices and whipped cream.