Preheat the slow cooker if necessary; see the manufacturer's instructions. Line the base and sides of a soufflé dish, 14 cm (5½ inches) in diameter and 9 cm (3½ inches) high, with nonstick baking paper, checking first it will fit in the slow cooker pot. Line the base with the trifle sponges, trimming them to fit in a single layer.
Put the cream cheese and sugar in a bowl, then gradually whisk in the cream until smooth and thick. Gradually whisk in the eggs one at a time, then mix in the lemon rind and juice. Pour the mixture into the dish and spread it level.
Cover the top with buttered foil and lower it into the slow cooker pot. Pour boiling water into the pot to come halfway up the sides of the dish. Cover with the lid and cook on high for 2–2½ hours or until the cheesecake is well risen and softly set in the centre.
Lift the dish out of the slow cooker pot using a tea towel and leave to cool and firm up. The cheesecake will sink quickly as it cools to about the size that it was before cooking. Transfer to the refrigerator to chill for at least 4 hours.
When ready to serve, loosen the edge of the cheesecake with a knife, turn out on to a serving plate, peel off the lining paper and turn it the right way up. Mix the jam and lemon juice in a bowl until smooth, add the sliced strawberries and toss together. Spoon on top of the cheesecake and serve immediately.