Preparation method

Cake:

• Preheat oven to180 C
• Grease 3 x 22cm sandwich tins and line the base with baking paper
• Sift the dry ingredients into large mixing bowl
• Add remaining ingredients with the juice from the pineapple
• Mix to combine, then divide over the three tins
• Spoon into tins and bake for 45 minutes, until an inserted skewer comes out clean
• Leave to cool in pans, then invert onto cooling racks and remove paper

Marshmallow frosting:

• Place egg whites, sugar, salt and cream of tartar over simmering water
• Do not let the bottom of bowl touch the water
• Whisk for 3 minutes until warmed and sugar is dissolved
• Remove from heat and beat on high speed until stiff and glossy
• Add vanilla and mix
• Stack cakes with thin layer of frosting
• Pipe with a decorative pattern

Sweet potato shards:

• Peel the sweet potato and then peel long strips
• Bring the sugar and water to the boil
• Add sweet potato and simmer slowly, until soft and slightly translucent
• Drain and lay strips crinkled on a non-stick sheet
• Bake at 100 C for 50-60 minutes, until almost crisp

Marshmallow fondant:

• Melt marshmallow, 1 tbsp margarine and 2 tbsp water
• Add icing sugar as soon as marshmallow mixture is lukewarm
• Add icing sugar one cup at a time until you reach thick and firm icing
• Knead on a clean surface until smooth
• Colour and shape fondant into the shape of a sweet potato
• Cut slices of the fondant sweet potato to decorate the cake