Use a food processor to blitz the cake into crumbs
Depending on how much your cake weighs, you need half the amount of full fat cream cheese. Mine weighed 700g so I used 350g cream cheese. Mix the cake crumbs and cream cheese together
Use your hand to roll chunks of the mixture into balls. You can weigh them out to make sure they are all the same size - aim for 25g per truffle
Lay the cake truffles onto a baking tray lined with baking paper, and put them into the freezer for 1 hour
Melt the white chocolate by breaking it into squares and microwaving it for 30 seconds. Then microwave in 10 second blasts, stirring between each one, until fully melted. Then mix in the orange food colouring
Use a fork to dip the cake truffles into the melted chocolate, lift them out and gently shake the fork over the bowl to remove any excess chocolate. Put them onto some baking paper to set
Use a clean paint brush to paint the black food colouring onto the cake truffles in a Jack O Lantern pattern
Store leftovers in the fridge and eat within 5 days
Notes
It doesn't matter how much leftover pumpkin cake you have, you just need to half the amount it weighs to get the weight of your cream cheese!