Slice pumpkin thinly and cut into 1/8" thick matchsticks.
Put pumpkin slices in a bowl and sprinkle with sugar and salt, toss together, and let it sit for 15 minutes to extract moisture. Do not drain.
Add flour and mix well. Adjust amount of flour depends on the amount of liquid extracted from pumpkin. let the mixture sit for 5 minutes.
Heat 1 tablespoon of oil in a skillet over med-low heat. Spread 2-3 tablespoonful of pumpkin batter to thin layer (Adjust the size of pancakes as you desire). Place chili slices on top, if using.
Cook 2-3 minutes on each side or until you get slight golden crust on both sides and the pumpkin gets soft. Press with a spatula gently to sear the surface as you flip to the other side. Drizzle more oil when needed.
Serve hot with dipping sauce. The pancakes is good either way, with or without the dipping sauce.