Butter four x 6 oz (¾ cup / 175 ml) pudding moulds or ovenproof dishes. You could also just use one large ovenproof or pudding dish that would hold about 24 oz (3 cups / 700 ml.)
Put 2 tablespoons of the jam in the bottom of each (or if using one large dish, dump it all in.)
Beat the rest of the ingredients in a bowl until smooth; pour into pudding dishes and level the surface with a knife or spatula.
Put the pudding dishes into a large ovenproof dish such as a casserole or roasting pan, and fill that dish or pan with 1 inch (2 to 3 cm) of boiling water. Place CAREFULLY into the oven. Or, place the dish in the oven first with the pudding dish/dishes in it, then pour the hot water in.
Cook until risen and golden, about 25 minutes.
Serve hot.
Notes
Instead of the flour, baking powder, and salt you can just use ½ cup (2 ½ oz / 70 g) self-raising flour.