By all means change the topping to a seasonal fruit coulis of your choice if you can’t get a hold of fresh passion fruit. In the winter months tinned cherries also make a delicious alternative.
Line a 26cm spring form tin with baking paper. Crush the biscuits using a plastic bag and rolling pin or process the biscuits to a crumb in a food processor. Add the melted butter and combine. Spoon the biscuit mix into tin. Smooth and flatten down with the back of a spoon. Cover and keep refrigerated until required.