Fill a large glass bowl to 1/3 with sponge cake broken into pieces. Spread the raspberry jam over the layer. Fill the next 1/3 of bowl with the drained fruit. You can use fruits other than the ones mentioned eg. banannas, pineapple,etc. Save the juice and sprinkle enough over the trifle to moisten the cake. Don't soak it. Add the sherry next. Now, make a custard by mixing the Bird's powder and sugar in a saucepan over medium heat. Gradually add the milk, stirring to blrnd. Cook and stir until the mixture comes to a full boil andthickens. Cool and spread over fruit layer. Cover this with whipped cream to which a little sugar has been added. Garnish with marachino cherries or choclate sprinkles. Cover with saran wrap and keep in fridge until ready. Can be made the night before.