You can steam your Pumpkin Spice Flan in the oven, in an instant pot, or even in a large pot with water on the stovetop. If you will steam it in the oven, fill a large, deep baking pan with hot water about 2" deep. Carefully place it in the oven and preheat it to 350F. For the other two steaming methods, please read notes below this recipe.
Make the caramel: In a heavy saucepan, over low-medium heat, melt the 3/4 cups of granulated sugar. Once melted, carefully pour it into a round baking/Bundt cake pan and swil caramel to cover bottom and walls of pan, while the caramel is still liquid. Set aside and allow the caramel to cool down for 10 minutes.
Make the flan: In the blender combine milks, eggs, pumpkin and pumpkin spice. Blend perfectly until smooth.
Pour flan mixture into the pan, over the caramel. Cover with foil. Water should not get into the flan. Carefully place into the large pan in the oven and steam for 1 hour 10 minutes to 1 hour 20 minutes, depending on your oven.
Once done, carefully pull flan out of the oven. Allow it to cool down for 2 hours, then refrigerate for at least 4 hours before serving. To umnold, run a thin sharp knife along the inside edges of the pan and flip pan oven serving dish. Spoon caramel in the pan over the flan.
Garnish as desired. Enjoy!