Method

• 1.
  For the jelly, soak gelatine in cold water for 5 minutes to soften. Combine sugar cubes and bitters in the base of a 16.5cm, 4L glass trifle bowl and crush cubes with the end of a rolling pin. Add 2 cups (500ml) sparkling water and bourbon, and stir to combine. Place remaining 1/4 cup (60ml) sparkling water in a saucepan over medium heat and cook until hot. Squeeze excess liquid from gelatine and stir through hot sparkling water until dissolved. Stir gelatine mixture through bourbon mixture. Chill for 3 hours or until set.

• 2.
  Preheat oven to 180°C. Grease base and side of a 20cm round cake pan and line with baking paper.
• 3.
  Meanwhile, to make the caramel treacle cake, melt butter, treacle and dulce de leche in a saucepan over medium heat. Stand for 10 minutes to cool. Sift flour and bicarb into a bowl. Stir eggwhite through treacle mixture, then add to flour mixture and whisk until smooth. Fold through 1/4 cup (60ml) hot water. Pour batter into prepared pan and bake for 25 minutes or until a skewer inserted into the centre comes out clean. Invert cake onto a wire rack to cool completely.
• 4.
  To make the bitter orange, place orange, 1/2 cup (110g) caster sugar and 1 cup (250ml) water in a large frypan and place over high heat, stirring until sugar is completely dissolved. Bring to the boil, reduce to a simmer and cook, turning halfway, for 20 minutes or until orange is tender. Using tongs, transfer orange to a baking tray and drizzle with bourbon and bitters. Preheat oven grill to high and grill orange slices, checking regularly, for 3 minutes or until caramelised. Set aside to cool completely.
• 5.
  To make the beer-nut praline, spread nuts evenly across a baking tray lined with baking paper. Combine 1/3 cup (80ml) water and remaining 1 cup (220g) caster sugar in a saucepan over high heat and cook, stirring constantly, until sugar is dissolved. Bring to the boil and cook, without stirring, for 5 minutes or until dark golden. Working quickly, pour sugar mixture evenly over nuts. Stand until completely cooled, then break into pieces.
• 6.
  Trim cake to fit neatly above jelly in trifle bowl, then carefully place on top of jelly.
• 7.
  When ready to serve, top cake with sour cream and half the orange slices, then scoops of caramel sorbet and remaining orange slices. Scatter with praline and serve immediately.