1. Preheat the oven to 350°F.
For the caramel base:
1. Melt sugar with water in a small copper or heavy-gauged saucepan over moderate heat. Stir occasionally to melt sugar.
2. Let the mixture boil without stirring for at least 5 minutes until the liquid turns golden brown.
3. Immediately pour into a 9" baking dish.
For the flan:
1. Mix the pumpkin, evaporated milk, egg substitute and vanilla in a bowl by hand or mixer.
2. Add the dry ingredients and blend well.
3. Pour the mixture into the prepared baking dish.
4. Place the dish in a larger pan and pour hot water into the larger pan until the water comes halfway up the edge of the baking dish.
5. Bake for 1 hour or until the flan is set.
6. Cool until room temperature then refrigerate for at least 4 hours and up to 1 day before serving.
7. Before serving run a sharp knife around the edge of the flan and invert onto a platter making sure that the caramel runs down the top and sides.