Mix the pumpkin, flour, egg, milk, cheese, baking powder, salt and pepper in a big bowl. Stir to combine well. The mixture should barely bind together and not wet or watery.
Using a spoon, scoop up the pumpkin mixture and drop it gently into the hot oil. Fry in batches until both sides turn golden brown and the inside is cooked through. Remove from oil with a strainer and transfer the fritters on a plate lined with paper towels. Serve hot with Thai sweet chili sauce.