Pour the flour into a bowl and make a well. Add sunflower oil, yeast, ginger, and salt. Dilute with a little warm water until the dough forms a ribbon. Incorporate the lightly beaten egg white. Reserve the dough for 2 hours at room temperature, covered with a cloth. Heat the frying oil. Shape the dough into donuts using 2 tablespoons and fry them until golden brown. Drain them on paper towels and let them cool. Pour the jam into a piping bag and fill the open donuts in half. Sprinkle with powdered sugar and serve.