Whisk sugar and egg yolks until thick and pale. Fold in the semolina,almonds,lime juice and rind,liqueur and salt. Whisk egg whites until stiff peaks form and fold into semolina mixture.
Pour into a buttered and floured 20cm springform pan and bake at 180C for 40 minutes or until golden and springy to touch. Stand in pan for 5-10 minutes before turning out on to a wire rack to cool.
For the filling
Beat ricotta,sugar and cream together until smooth.
Cut cake in half horizontally,spread lemon curd over bottom half of cake,then ricotta mixture,then replace top half of cake.
To serve,dust with icing sugar and decorate with crystallised flowers and eggs.