Heat the oven to 180°C, 160°C fan, gas 4. Line the base and sides of a (roughly) 25 x 20 cm traybake tin with baking paper.
Put the cherries and teabag in a small bowl and pour over 200ml boiling water. Leave to soak for an hour then strain and stir 2 tbsp Damson Plum Conserve into the cherries.
In a large bowl, whisk together the sugars, oil, eggs and ginger. Stir in all the dry cake ingredients and finally stir in the cherries, carrots and nuts.
Spoon into the tin and bake for 40 minutes. Cover loosely with foil and bake for a further 10-15 minutes or until a skewer comes out clean. Cool.
Gradually beat the yoghurt into the mascarpone and add the vanilla and 1-2 tsp caster sugar to taste.
Spread the top of the cold carrot cake with Damson Plum Conserve then spoon over the mascarpone frosting. Store in the fridge but allow about 20 minutes at room temperature before serving.
We decorated the top of our carrot cake with chopped fresh plums, cherries and caramelised pecan nuts. The cake, minus the frosting, will freeze.