Tawny Port is great with chocolate, yet light enough to perfectly complement the citrus fruit. The alcohol in the wine complements the abundance of chocolate, it also contributes spice, which harmonizes wonderfully with the mulled wine spice.
Peel oranges, grapefruits, limes, and lemon. Supreme citrus fruits, set the segments aside, and press out the juice from the remaining membranes. Add juice to a saucepan.
Combine starch and water in a small bowl to make a slurry. Halve vanilla bean and scrape out the seeds. Add to saucepan, together with sugar and mulled wine spice. Bring to a boil and add the slurry. Let reduce by half, then strain over citrus segments and toss to coat. Season to taste with honey and set aside.
Preheat oven to 180°C/350°F. Grease baking molds. Dice butter and chop chocolate. Melt both in a heatproof bowl set over a small saucepan of simmering water.
Meanwhile, add eggs to a mixing bowl, then add half of the sugar and beat until foamy. Add remaining sugar and melted chocolate and stir slowly. Sift in flour and stir gently.
Distribute the dough into the molds, transfer them onto a baking sheet, and bake at 180°C/350°F for approx. 10 min., until tops are firm but cakes wobble slightly when jiggled.
Serve citrus salad on a plate, release cakes from molds, and place them directly on top. Garnish with confectioner's sugar and enjoy!