Preheat the oven to 180°C fan. Grease and line the bottom and sides of two ramekins with butter and greaseproof paper.
Finely grate the zest of the mandarin into a small bowl and set aside. Peel the mandarin and cut it in half. Juice one half into a bowl and separate the other half into segments.
Use a spoon to fold the flour into the cake batter. Add 2 tsp of mandarin juice and most of the mandarin zest (reserve some for garnish) to the batter and mix gently until combined.
Put 1 tsp of the mandarin syrup (that you made earlier) into the bottom of each greased & lined ramekin. Put some fresh mandarin segments in both ramekins. Add the cake batter to the top of the mandarin segments. Use a spoon to smooth-out the tops of the cakes.
Using oven gloves, put a shallow bowl or plate on top of each ramekin, turn each cake upside down and remove the ramekins.
To serve (hot or cold): Pour cream around the base of each cake and garnish with finely grated mandarin zest.
Ramekins - I use round ramekins that are 9cm in diameter and 4.5cm in height.