Preheat Oven to 350F
Place flan pan on the stove over a medium flame. Add the Demerara sugar and water, and stir to dissolve. Let the sugar mixture come to a boil, reduce the heat slightly, and let it bubble until it becomes brown and syrupy; about 7 to 8 minutes. Watch carefully and don't allow the sugar to burn -- it can ignite quickly. Set the pan aside to cool.
In a blender, combine the instant espresso powder, sweetened condensed milk, evaporated milk and eggs, and whirr until the espresso powder is dissolved and the mixture is well blended.
Pour the coffee mixture over the cooled sugar syrup. Clip the lid on the pan. Set the pan inside a larger pan Carefully pour in almost boiling water to reach 2/3 of the height of the inside pan. Place in oven and bake for about 50 minutes or until a knife inserted in the middle of the flan comes out clean. Remove the flan pan from the water and chill in the refrigerator for at least 2 hours.
To unmold: Loosen the sides by running the blade of a knife around the inner circumference of the pan. Pour a little hot water into the larger pan originally used for the water bath. Set the flan pan into the hot water for 20 to 30 seconds to loosen the bottom. Place a serving plate face down on top of the flan pan and invert onto the plate. T
To serve: Cut the flan into 8 pieces and serve on individual plates.
The owner of this pot de creme cup describes it as being from the Napoleon III era from the Sevres factory in France