1. Preheat the oven to 180°C/fan 160°C/350°F/gas mark 4. Butter a 23cm round springform tin and line the base and sides.
2. Put the desiccated coconut over low heat and stir until it is a pale golden brown. Set aside to cool.
3. In the bowl of a food mixer, or in a large bowl using a hand-held electric whisk, or using a food processor, place all the ingredients except the raspberries and demerara sugar. Mix together only until it becomes an even cake batter.
4. Transfer to the prepared tin and scatter evenly with raspberries. Sprinkle with demerara sugar and bake in the preheated oven for 35-40 minutes. Cool in the tin on a wire rack for five minutes, then remove from the tin and cool slightly.