For the Vanilla Cake: Preheat convection oven to 320°F (160°C). Grease a 9-inch ovenproof bowl. Sift together flour, baking powder, and salt in a medium bowl. Set aside. Using a kitchen mixer, cream together the butter, oil, sugar, and vanilla until light and fluffy. Add the eggs one at a time, mixing until combined. Fold in the flour mixture and the milk in one-third increments, alternating between them. Fold until just combined. Pour mixture into prepared bowl and bake for 45-50 minutes or until a skewer inserted into the center comes out clean. Stand cake in bowl for 1 hour, before turning onto wire rack (top-side down) to cool completely. Cover with plastic wrap or a clean, damp tea towel and set aside until assembly. For the Marshmallow Puffs: You will need: 3 large piping bags; 3 semi-sphere silicone molds (Varying sizes, greased with cooking oil spray. I used 2cm, 5cm and 9cm). To make your first batch of marshmallow puffs, place 250g sugar and 130g of water in a large, heavy based pan. Put the candy thermometer in, and turn on the heat. Without stirring, allow the sugar syrup to heat and boil until it reaches 250°F (120°C) on the thermometer. Meanwhile, place 70ml of hot?water in a cup or small bowl and add 20g gelatin powder. Add flavoring, as desired. Once the the sugar syrup reaches around 230°F (110°C), whip 3 egg whites to firm peaks in the bowl of a kitchen mixer. Remove sugar syrup from heat at 250°F (120°C), then gently stir in the gelatin mixture until well combined. With the kitchen mixer on highest speed, continue to whip the egg whites while carefully pouring in the hot sugar syrup. Continue to whip until mixture thickens and increases in volume, whilst also remaining pourable. Mix in food color (I used pink) until a desired shade is achieved. Working quickly, transfer into 1 large piping bag and use scissors to snip 2cm off the end. Quickly pipe the marshmallow into all silicone cells, until level. Place into refrigerator for at least 1 hour or until completely set. To remove marshmallows from mould, lightly oil your hands with a small amount of cooking oil spray and gently pop out one by one, rolling each one generously in the coconut. To make your second color of marshmallow puffs, respray silicone molds with cooking oil spray. Repeat Steps 1-5 and color marshmallow mixture with a separate color (I used apricot). To make your final batch of marshmallow puffs, respray silicone moulds with cooking oil spray. Repeat Steps 1-5 and color marshmallow mixture with final color (I used violet). Tip: Store leftover marshmallows in an air-tight container in the fridge for up to 7 days. You can freeze marshmallows in an air-tight container for up to 1 month. Tip: You can also flavor your marshmallow with fruit puree or natural flavoring extracts. For the Cream Cheese Frosting: You will need: 1 piping bag. For the frosting, use an electric mixer to beat the cream cheese and butter until fluffy. Gradually add the icing sugar while beating. Add the lemon juice and beat until fluffy. Use a long, thin knife to divide your cake horizontally into 3 layers. Place a dollop of cream cheese frosting onto a cake board or large serving plate and place the bottom layer of cake on top (this should prevent your cake from sliding around!). Use an offset spatula to apply a layer of cream cheese on top. Fill piping bag with cream cheese and pipe a 1cm thick barrier around the inner edge of cake layer (this will create a well to be filled with raspberry jam). Fill with raspberry jam and gently place second layer on top. Repeat this process with the second layer, this time using cream cheese and lemon curd. Gently place final layer on top and use an offset spatula to crumb coat cake with cream cheese frosting. Plate in refrigerator for 20 minutes to firm. Frost cake with remaining cream cheese frosting and completely cover (I start around the bottom edge) with assorted marshmallow puffs. Once decorated, you can use remaining desiccated coconut to fill in any small gaps between marshmallow puffs. This cake is best enjoyed on the day of decorating and served at room temperature. Can be refrigerated (wrapped in plastic wrap) for up to 4 days.