Method

• 1.
  For the preserved ginger syrup, use a large knife or mandoline to thinly slice the ginger lengthways into 2mm-thick long strips. Place in a large saucepan and cover with 12 cups (3L) cold water. Bring to the boil over high heat, then reduce heat to medium and simmer, partially covered and stirring occasionally, for 30 minutes, or until ginger is just tender when pierced with a toothpick. Drain, reserving ginger and 4 cups (1L) of ginger water.
• 2.
  Place the caster sugar and reserved ginger water in a medium saucepan over medium-high heat. Bring to a simmer, stirring constantly, until the sugar has dissolved. Add the ginger and simmer, stirring occasionally, for 40 minutes, or until ginger is softened and light golden in colour and liquid is reduced and syrupy. Remove pan from heat, cover and cool to room temperature. Reserve 1/2 cup sliced ginger and 2-3 tbs syrup from the pan in an airtight container to serve. Cut remaining sliced ginger into thin matchsticks, then transfer to an airtight container and pour over remaining syrup. Chill until serving (or store, chilled, see notes).
• 3.
  Preheat oven to 180°C/160°C fan-forced. Grease base and sides of 2 x 18cm round cake pans and line with baking paper. Line a large baking tray with baking paper. Place the butter and sugars in a stand mixer fitted with the paddle attachment. Beat on medium-high speed for 3 minutes or until pale and creamy, scraping down side of bowl occasionally. Add eggs, molasses and vanilla and beat on medium-high speed until well combined. Add flour, spices, baking powder and buttermilk and beat on medium-high speed until well combined, scraping down side of bowl occasionally. Divide batter evenly between prepared cake pans and level surface. Bake pans side by side in oven for 45 minutes, swapping pans around on shelf halfway during baking, or until a skewer inserted at centre comes out clean and top is deep golden brown. Transfer to wire racks to cool completely in pans.
• 4.
  Preheat oven to 180°C/160°C fan-forced. Remove cakes from pans. Trim the domed tops of both cakes, transfer the trimmings to the prepared baking tray and use your fingers to crumble trimmings into crumbs. Shake tray so cake crumbs are in a single layer, then bake for 10-12 minutes, until crumbs are dry and crisp. Cool on tray.
• 5.
  For the icing, place the mascarpone and cream in a stand mixer fitted with the whisk attachment. Whisk on medium-high speed until soft peaks form. Add icing sugar and whisk on medium speed until well combined and firm peaks form.
• 6.
  To assemble, slice each cake in half horizontally. Place base of one cake onto a serving plate and spoon over 1/4 cup of the preserved ginger matchsticks, then drizzle with 1 tbs ginger syrup. Spoon 1 cup of mascarpone icing on top, spreading out to edge of cake. Repeat this process twice more, then finish with a top layer of cake. Drizzle the cake top with 1 tbs ginger syrup.
• 7.
  Use the remaining mascarpone icing to spread a thin layer over top and side of cake to give it a ‘naked’ effect. Chill cake for 1 hour, or until icing has set firm. When ready to serve, decorate top with eucalyptus leaves and serve with reserved sliced ginger and cake crumbs alongside.