Method

• 1.
  For the vanilla cake, preheat the oven to 160°C fan-forced. Grease three 15cm-diameter shallow round cake tins and a 15cm ovenproof bowl
• 2.
  Sift the flour and ¼ tsp salt into a bowl. Using an electric mixer, beat the butter, oil, sugar and vanilla until frothy. Add the eggs, one at a time, and mix until combined.
• 3.
  Alternately fold in the flour mixture and the milk in one-third increments. Fold until just combined.
• 4.
  Divide the batter among the tins and bowl. Bake the cakes (in batches if necessary) for about 30 minutes or until a skewer inserted into the centre comes out clean. Leave to cool briefly before turning out onto wire racks (with the tops facing down) to cool completely. Cover the cold cakes with plastic wrap or a clean, damp tea towel and set aside until needed.
• 5.
  For the pineapple curd, add pineapple purée, lemon juice, sugar, yolks, cornflour and a pinch of salt to a saucepan and whisk to combine. Place pan over medium heat and whisk continuously for 5 minutes or until the mixture thickens (this happens just as it’s about to come to the boil). Remove from the heat. Add the butter and whisk until melted.
• 6.
  Transfer the pineapple curd to a jar and refrigerate until thickened and cooled before using to fill the cake.
• 7.
  For the vanilla bean Swiss meringue buttercream, put the sugar and egg whites in a heatproof glass bowl. Set the bowl over a saucepan of gently simmering water and whisk until the sugar has dissolved and the mixture is slightly warm to the touch. Remove from the heat
• 8.
  Using an electric mixer fitted with the whisk attachment, beat egg white mixture on high speed until stiff and glossy peaks form (10-15 minutes).
• 9.
  Add the butter a piece at a time, beating well after each addition (don’t rush this process). Add the vanilla and beat until fluffy. Transfer a third of the buttercream to a bowl and tint the remaining yellow. Cover and set aside in a cool place.
• 10.
  For the assembly, working on a cake turntable or lazy Susan, secure the bottom layer of cake onto a cake board or plate with a dollop of buttercream and then gently twist in place.
• 11.
  Place untinted buttercream in a piping bag and pipe a 1cm border around the edge of the cake to create a well. Fill the well with pineapple curd and place the second cake layer on top. Repeat the buttercream and pineapple curd as for the first layer, then again for the third. (Refrigerate the cake between layers to help it firm up, especially if it’s a hot day.)
• 12.
  Using an offset spatula and a cake scraper, gently crumb coat the side of the cake with a thick layer of untinted buttercream, filling in any gaps between layers and spreading the buttercream up. Level the top of the bowl cake and gently place upside down on top of the layered cake. Crumb coat the top of the cake. Chill in the refrigerator for 20 minutes.
• 13.
  Place the yellow buttercream in a piping bag fitted with a star nozzle (I used a Wilton 1M metal tip). Working from the base, pipe buttercream all over cake.
• 14.
  For the decoration, push the cake dowel into the bottom of the pineapple top until the length of dowel remaining is the same height as the cake. Push the dowel into the cardboard round, then gently push the dowel into the cake until secure.