Method

• 1.
  Place orange in a pan and cover with water. Bring to the boil, then simmer on low heat for 45 minutes until soft. Cool.

• 2.
  Preheat oven to 180°C and grease a 24cm springform cake pan.
• 3.
  Quarter orange, discard seeds, then puree in a food processor with butter, brown sugar and carrot. Add eggs through the feed tube one at a time until combined. Add the hazelnut meal and whiz for a few seconds to just combine. Transfer to a bowl, then sift over the flour and gently fold in with a metal spoon.
• 4.
  Spread mixture into cake pan, then bake for 45 minutes or until a skewer inserted in the centre comes out clean. Cool in the pan for 10 minutes, then transfer to a rack to cool.
• 5.
  Meanwhile, lightly froth eggwhite in a bowl with a fork. Place sugar in another bowl. Dip rosemary sprigs into egg, then dust in caster sugar. Set aside to dry.
• 6.
  Warm marmalade and liqueur in a pan over low heat with 1/2 cup (125ml) water, stirring to dissolve. Strain to remove the peel, then stir in nuts and keep warm.
• 7.
  Lightly whisk together the mascarpone cream ingredients to combine. Cut the cake into slices and place on plates. Spoon over the syrup and nuts, then serve with mascarpone cream and garnish with sugared rosemary.