Preheat oven to 350°F/177°C. Prepare one 6-inch tin cake and 3-inch tin can.
For the cake: In a bowl, mix all cake ingredients together, divide it among the two cans. Bake in the preheated oven for 20-25 minutes.
For the syrup: In a small sauce pan, heat up sugar with the water. Once the sugar is melted simmer for 2-3 minutes. Remove from the heat and pour in white rum.
Remove cakes in the oven and pour syrup over the two cakes.
For the custard: Mix all ingredients in a heat-proof bowl and cook over a double boiler. Cook until it coats the back of the spoon and is thickened. Strain the mixture. Pour this into the prepared cakes.
Refrigerate to set. Sprinkle sugar on top, torch lightly to melt and caramelize the sugar.
Yield: one 6x3 ½ -inch & one 3x3 ½ -inch tin can cake