Preheat the oven to 350 degrees F (180 C).
Pour the caramel sauce into a steam pudding pan (one that has a lid and a hole in the middle) and spread the caramel sauce around the pan with the help of a silicone basting brush or a small spatula.
Then, add the coconut condensed milk, soy milk, eggs, pumpkin puree, and spices into a blender and blend until smooth.
Place the steam pudding pan in the center of a baking dish (with high sides to make a water bath), pour the flan mixture inside the steam pudding pan, and cover with the lid.
Next, add boiling water into the baking pan until it reaches at least halfway up the sides of the pan.
Place the baking pan very carefully inside the oven (use oven gloves and be careful not to burn yourself), and bake for 60 minutes.
After 60 minutes, carefully remove the pudding pan from the oven (without opening the lid) to a wire rack and let it cool down for 1 hour. Then, refrigerate overnight. Unmold after refrigerating overnight.
To unmold, invert the pan into a large serving plate. Keep it in the fridge until serving. You can add more caramel sauce on top before serving.