Rub some oil around the inside of a 20cm/8” round deep cake tin or insert a cake liner.
Take a quarter of the marzipan and divide it into 11 small pieces. Roll the small pieces into small balls.
Dust the work surface with a little icing sugar, take half of the remaining marzipan and roll into a circle just larger than the cake tin. Place the tin on top of the marzipan circle and cut around the outside to make a perfect circle. Cover and set aside all the marzipan.
Pre-heat the oven: 170°C, Fan 150°C, 325°F, Gas 3.
Put the flour, xanthan gum and mixed spice into a bowl and stir to combine.
Peel and grate the apple into a large mixing bowl, add the sugar, oil and water and beat well.
Add the prepared flour to the bowl and beat well.
Stir in the mixed dried fruit.
Tip half the mixture into the prepared cake tin and smooth the top.
Take the prepared marzipan circle and place it on the cake mixture.
Put the remaining cake mixture onto the marzipan and smooth the surface.
Bake for 1½-1¾ hours. Allow to cool in the tin for at least 30 minutes before turning out onto a wire rack to cool.
Warm the apricot jam and brush half over the top of the cold cake.
Roll the remaining marzipan into a circle just larger than the cake tin. Place the tin on top and cut a zig-zag pattern around the outside.
Gently lift the marzipan on top of the apricot brushed cake.
Brush the base of each prepared marzipan ball with jam and place them in a circle on the top of the cake.
Place the cake under a hot grill for a few minutes to lightly brown the marzipan.
Store the cold cake in a tin.