Line a 20 cm (8 inch) springform tin with nonstick baking paper. Soften the gelatine in cold water.
Mix together the biscuit crumbs and melted sunflower spread and press into the prepared tin. Refrigerate.
Sieve together the cottage cheese and ricotta. Beat the egg whites until stiffly peaking, then beat in the icing sugar until glossy.
Put the lemon juice and 50 ml (2 fl oz) water in a saucepan over a low heat and stir in the gelatine until dissolved. Add to the ricotta mix with the maple syrup, then fold in the egg whites. Pour the mixture over the biscuit base and refrigerate until set.
Decorate with the sliced oranges and sprigs of redcurrants before serving.