Beat the flour, sugar, oil, eggs, and milk together.
Add the can of pumpkin, blending in well.
Blend in the cinnamon and coriander well. If you want it to have more of a pumpkin pie taste, use 2-3 teaspoons pumpkin pie spice instead.
Grease a 9x13 glass baking dish with some canola oil (about a tablespoon or two) and pour the mixture into it, dispersing evenly.
Bake at 350F for 65-70 minutes (only 60 if you used non-dairy milk.).
Let cool for at least 15-20 minutes prior to eating. It's delicious warm, but I like it better cold with some SoyWhip and extra cinnamon sprinkled on top! It also microwaves well if you want to eat it warm (nuke a medium-size square about 30 seconds on high.).
Rolled oats and raw green pepitas also make nice toppings to add to this after the souffle has baked at least 30 minutes.