To begin with place the diced strawberries, passion fruit pulp and sugar into a small bowl and stir until all the fruit is covered in sugar. Leave to one side to macerate.
Place the double/heavy cream and sugar into a medium sized bowl and whisk until stiff peak. You want to pull the whisk out and have the peak stand up, but the tip will just bend over. Leave to one side.
If you're using traditional custard, you won't need to do this step, move straight to assembly. With Oatly custard you need to whisk it until it thickens and holds its shape, so place in a medium bowl and whisk.
To Assemble: Take 4 individually sized jars/dishes and place a few cake cubes into the bottom of each jar. Then spoon a large tbsp of the strawberry mixture on top of the cake. Spoon around 2tbsp of custard over the fruit and then repeat the cake, fruit, custard layers until you've used all the custard and cake cubes. I got two full layers of each. Reserve some of the fruit mixture for topping.
After the final layer of custard, spoon 2tbsp of whipped cream onto the custard. Oatly custard is very pale when whipped so almost looks like cream in my photos, traditional custard will be much more yellow of course.
Once all the trifles are topped with whipped cream, spoon a little of the remaining fruit mixture onto each trifle, for garnish.
Strawberry Passion Fruit Trifles will keep covered, in the fridge fo 2 days, but are best eaten same day. Best served chilled.