Preheat the oven to 190°C, GM 5, 375°F.
Heat a lined greased oblong baking tin (10 x 8 inch, 26 x 19 cm) by placing in the preheated oven for a couple of minutes. Add 2 tbsp golden syrup to the baking tin and gently tip from side to side to allow it to spread over the base. Help it with a spatula if needed. Place drained tinned mandarin oranges and blackberries or raspberries on the base and top with the pudding mixture made as follows:
Simmer 3 oranges in boiling water for 1 hour. Drain, cool, cut into sections, remove any pips and place in a blender or food processor. Process until no lumps or pieces of peel remain. Transfer to a bowl and add the beaten eggs and the rest of the ingredients. Mix well and pour on top of the fruit in the tin. Bake in the centre of the oven for approx 45 minutes or until firm to the touch and a skewer comes out clean if inserted in the centre. Turn out onto a wire rack with fruit uppermost. Serve warm with dairy free custard, cream or ice cream.