This is a really simple yet attractive cake for any party!
With a Digestives crust, just bake a basic cheesecake (recipe here), and let it chill overnight in the fridge. For the jam topping, just take about 1/2 cup of your favourite jam, add a couple of tsp of water (unless your jam is already runny), and warm it up till it's a more liquid consistency. Pour over the top of your cheesecake and smoothen with a spatula if necessary. Back into the fridge it goes for at least half hour to set.