Preheat the oven to 180°C.
Line a 23cm springform tin with parchment and grease with olive oil.
Toast the pine nuts in a dry frying pan until browned.
Grate carrots and squeeze out excess liquid using kitchen paper.
Simmer sultanas in 60ml rum for 3 minutes then set aside.
Whisk sugar and oil together until airy.
Mix in vanilla and eggs, then fold in almonds, nutmeg, carrots, sultanas, and lemon.
Pour the batter into the tin and smooth the surface.
Sprinkle with toasted pine nuts and bake for 30–40 minutes.
Cool the cake in the tin for 10 minutes before transferring to a rack.
Mix mascarpone with icing sugar and rum to create the cream.
Serve slices of cake with a dollop of mascarpone cream.