Method

• 1.
  Preheat oven to 160°C/140°C fan-forced. Grease a 21 x 31cm deep rectangular baking pan and line with baking paper.

• 2.
  Sift flour, cocoa and baking powder into a bowl. Add sugar and macadamia meal. Stir well to combine. Whisk egg and egg white together in a separate bowl. Stir into flour mixture with butter and buttermilk. Transfer to pan and bake for 45 minutes, or until a skewer inserted into the centre comes out clean. Cool in pan for 10 minutes before turning onto a wire rack to cool completely.
• 3.
  Meanwhile, combine raisins, spice, water and rum in a bowl. Set aside.
• 4.
  Remove base from a 20cm springform pan. Using base as a guide, cut out 1 piece from cake, then cut out 1 semi-circle piece. Cut each piece in half horizontally through centre (this will give you 4 pieces). Return base to pan, and line base and side with a double layer of plastic, leaving ends to overhang.
• 5.
  Spoon half the ice cream into a bowl to soften slightly. Place 1 full circle cake layer into the base of pan (this will be the top of the cake when it is turned out). Spread ice cream over cake and return to freezer for 20 minutes.
• 6.
  Combine raisin mixture, macadamia and chocolate sauce in a bowl. Spoon half of the raisin mixture over ice cream layer. Repeat layering, using the 2 semicircle layers (joining them to create 1 full circle), remaining ice cream and raisin mixture. Finish with remaining cake layer. Cover and freeze for 4 hours or overnight.
• 7.
  To make pineapple decorations, peel 1 pineapple and cut into thin slices 2mm thick. Pat slices dry with paper towel and lay on a wire rack over an oven tray. Bake at 120°C/100°C fan-forced for 2 hours, turning every 30 minutes until dry. To shape, lay into a muffin pan and leave to dry.
• 8.
  To serve, place a plate over the top of the springform pan and turn over. Remove cake pan and plastic. Dust top of cake with cocoa and decorate with pineapple and macadamia.