Preheat the oven to 200`c. Grease and line a 23cm x 30cm Swiss roll tin. Whisk the eggs and sugar in a bowl until pale and fluffy. Fold in the flour and spoon the mixture into the tin. Bake in the oven for 8-10 minutes, or until light and springy to the touch. Remove from the oven and turn the sponge out onto another piece of greaseproof paper. For the filling, spread the jam onto the sponge. Whip the cream with the icing sugar and spread over the jam, leaving a small gap around the edges. Place a row of raspberries along one edge, lengthways and roll up the sponge to cover the raspberries and create a lovely Swiss roll. Place onto a serving plate, dust the top with icing sugar and decorate the top with extra raspberries.