Method

• 1.
  To make the sponge, preheat oven to 190°C/170°C fan-forced. Lightly grease a 20cm springform pan and line base and sides with baking paper.
• 2.
  In a stand mixer fitted with the whisk attachment, whisk egg yolks with half the sugar on high speed for 4 minutes, or until pale and thick, scraping down side of bowl several times. Transfer to a large bowl. In the clean bowl of a stand mixer, whisk egg whites and remaining 45g sugar until a firm, glossy meringue. Fold one-third of meringue into egg yolk mix, then gently fold in the remaining. Sift flour and cornflour together over egg mixture and gently but quickly fold in until combined. Spoon into prepared pan, level surface with a spatula and bake for 25 minutes, or until a skewer inserted in centre comes out clean. Cool in pan on a wire rack to room temperature, then release from pan.
• 3.
  For the syrup, place all ingredients in a small saucepan with ¼ cup (60ml) water and bring to a simmer over medium-high heat. Simmer for 3-4 minutes. Pass through a fine strainer, discard solids and chill until ready to assemble.
• 4.
  For the cream filling, whisk yolks, sugar, milk and vanilla in a medium heatproof bowl until combined. Place over a saucepan of simmering water (don’t let base of bowl touch the water) and stir until it reaches 86°C on a digital thermometer (or has thickened to cover the back of a wooden spoon). Remove from heat.
• 5.
  Squeeze out the water from the gelatine and add to the yolk mixture. Stir until melted and smooth. Chill until cold. In a stand mixer fitted with the whisk attachment, whisk on high speed until thoroughly smooth. Transfer to a bowl. Place the creme fraiche and cream in the clean bowl of a stand mixer and whisk on medium speed until soft peaks form. Fold into the custard until combined, then transfer to a piping bag and chill until ready to assemble.
• 6.
  To assemble, halve the sponge horizontally using a large serrated knife. Trim 1cm from around each circle. Clean and dry the outer ring of the springform pan and place on a serving plate. Lightly spray with oil and line side with baking paper coming up about 8cm high.
• 7.
  Place a layer of sponge in pan ring on plate. Cut a 1.5cm opening in the piping bag and pipe a circle of cream on the sponge around outer edge, then arrange savoiardi biscuits upright around the edge of the pan ring to create a circumference of biscuits (there should be enough space for biscuits to fit between side of pan and sponge; the circle of cream will help stabilise the biscuits). Press biscuits down so they touch the plate. Using a pastry brush, lightly apply syrup to sponge and inside layer of biscuits, leaving 1cm unbrushed at the top of biscuits.
• 8.
  Pipe over half the remaining cream filling (a layer about 2-3cm deep), then cover with remaining sponge. Brush sponge with syrup, then pipe over the remaining cream filling. Use an offset spatula to smooth the top cream layer flat before topping with fresh raspberries. Ideally, the top layer of the cake should be about 1cm shorter than the top of the biscuits, leaving room for the raspberries to sit inside. Chill for at least 4 hours before serving.
• 9.
  Carefully release springform pan ring and baking paper. Dust with icing sugar to serve.