(click on the text to highlight each stage):
- For the cake: heat the oven to 170°C,325°F, gas 3. Grease and base line two 20 cm|8\" sandwich tins with a depth of 4 cm|1 1/2\"
- Sift the flour and baking powder into a mixing bowl, Add all the other ingredients, except the coconut and whisk with an electric whisk until smooth. Alteratively, beat well with a wooden spoon. Stir in the coconut. The mixture should have a soft dropping consistency- if it seems too stiff, add a little water.
- Divide the mixture between the tins and bake for 30-35 minutes, until springy to the touch and golden. Cool in the tins for 5 minutes, then turn out onto a wire rack to cool.
- Peel off the lining paper and carefully cut each cake horizontally into 2 halves, using a sharp bread knife.
- For the filling and icing: warm the jam gently and spread the jam on 1 cake layer.
- Put the shredded coconut, mascarpone, vanilla and icing sugar in a bowl and whisk until combined.
- Carefully spread a thin layer over the cake layer spread with jam. Place another cake layer on top and repeat with the jam and coconut filling. Repeat with the third cake layer and put the plain cake layer on top.
- Spread the rest of the icing over the top and sides of the cake and dredge thickly with shredded coconut.