Whisk pumpkin, egg, salt, nutmeg and baking powder in large bowl to blend.
Mix in flour (dough will be soft).
Dip 1/2 teaspoon measuring spoon into boiling water to moisten. Scoop up a generous 1/2 teaspoon of dough and return spoon to water, allowing dough to drop.
Working in two batches, repeat dropping 1/2 teaspoonsful of dough into water, first dipping spoon into water to moisten each time.
Boil dumplings until cooked through, about 10 minutes.
Using slotted spoon, transfer to colander and drain.
Melt butter in heavy large skillet over medium heat. Add dumplings. Sauté until beginning to brown, about 8 minutes.