Preheat oven to 375 degrees F (190 degrees C). Arrange pumpkin seeds in a single layer on a baking sheet. Toast in preheated oven for about 10 minutes, or until seeds begin to brown.
Melt butter in a large pot over medium heat. Stir in flour and curry powder until smooth. Cook, stirring, until mixture begins to bubble. Gradually whisk in broth, and cook until thickened. Stir in pumpkin and half-and-half. Season with soy sauce, sugar, salt, and pepper.
Bring just to a boil, then remove from heat. Garnish with roasted pumpkin seeds.