Preheat oven to 200°C. Spread rhubarb in a roasting dish. Sprinkle over sugar. Combine water, jam and vanilla in a jug, then pour over rhubarb. Bake for 12 minutes. Transfer rhubarb and syrup to an 8-cup capacity ovenproof dish. Cool slightly.
Put eggs in the large bowl of an electric mixer and beat until pale. Gradually add caster sugar, beating for 7-8 minutes or until creamy and tripled in volume. Do not overbeat or sponge will lose its volume. Sift all ours together twice, then sift again over egg mixture. Gently fold to combine.
Sprinkle raspberries over rhubarb and top with sponge mixture. Sprinkle over almonds. Bake for 30-35 minutes or until golden. Dust with icing sugar and serve with cream.