These are classic yeast-raised doughnuts, deep-fried, rolled in sugar, and filled with jam. A pastry bag fitted with a round tip makes it easy to fill them with jam, but you can also cut them in half and spoon the filling into the center.
1. Mix yeast and 1 tsp. sugar with 1 cup warm water (110°F) in measuring cup. Let stand 5 minutes, or until mixture foams and smells yeasty.
2. Whisk together flour, remaining 1/4 cup sugar, salt, baking powder, and nutmeg in large bowl. Grease separate large bowl with oil.
3. Stir yeast mixture into flour mixture with wooden spoon until sticky dough forms. Add up to 1/4 cup warm water to make smooth dough. Stir in melted margarine. Turn dough out onto well-floured work surface, and knead 6 to 8 minutes, or until smooth, soft, elastic dough forms. Add flour while kneading, if necessary. Transfer to oiled bowl, cover with towel, and let rise in warm place 1 1/2 hours.
4. Dust baking sheet with flour. Roll dough out to 1/4-inch-thick round on well-floured work surface. Cut 25 circles from dough with 2-inch round cutter. Transfer rounds to prepared baking sheet, and cover loosely with plastic wrap. Let rest 15 minutes.
5. Heat oil in large skillet or Dutch oven to 370°F, or until hot but not smoking. Fry doughnuts in oil 3 to 5 minutes, or until deep golden brown, turning two or three times. Drain on paper-towel-lined plate; then roll in superfine sugar while still warm. Cool.
6. Poke small hole in side of each doughnut with toothpick or wooden dowel. Use pastry bag fitted with small round tip to fill each doughnut with 1 tsp. raspberry jam.