It's because of his 1p. England's just jealous when he saw his 2p's cupcakes are better than his scones. So he got jealous and cursed something under his breath (2pEnglandOllie: SWEAR JAR!!!) before going home and learning a curse spell. He chose the death one, where if somebody touches or eats the object that has been cursed with that spell, they die. So the next day, for the 'Sweets Competition' England has already learnt the spell by heart. So when Oliver was distracted, he put the curse on those cupcakes and the ingredients that Oliver uses. The judges passes England's scones and goes to Oliver's cupcake. They eat it and die, just like the curse was suppose to do. So there you have it! Oliver's cupcakes were yummy and sweet at first, until his 1p cursed it.
