Sufganiyot (Jelly-Filled Doughnuts)

1 package dry yeast
1 1/4 cups warm milk (105 to 115 degrees F), divided
4 1/2 to 5 cups all-purpose flour, divided
4 egg yolks
2/3 cup granulated sugar
1 teaspoon vanilla extract
1 teaspoon grated lemon rind
1/2 cup butter, softened
1/2 cup raspberry or strawberry preserves
Vegetable oil

Dissolve yeast in 1/4 cup of the warm milk; let stand 5 minutes.

Combine 1 cup of the flour and remaining 1 cup warm milk in a large mixing bowl, mixing well at medium speed with electric mixer. Add yeast mixture; mix well. Cover and let rise in a warm place (85 degrees F), free from drafts, for 30 minutes.

Combine egg yolks and next 3 ingredients in a small bowl, mixing well; add to yeast mixture. Stir in butter and enough remaining flour to make a soft dough. Place in a well-greased bowl, turning to grease top. Cover and let rise in a warm place, free from drafts, 45 minutes or until doubled in bulk.

Punch dough down; turn out onto a lightly floured surface, and knead several times. Divide dough in half. Roll one portion to 1/4-inch thickness, leaving other portion covered; cut 24 circles with a 2 1/2-inch cutter. Place 12 circles on a lightly greased baking sheet. Place 1/2 teaspoon preserves in center of each circle. Brush edges of each jelly-topped circle with water. Place remaining 12 circles over jelly-filled circles; pinch edges to seal. Repeat procedure with remaining dough and preserves. Cover and let rise in a warm place, free from drafts, 45 minutes or until doubled in bulk.

Pour oil to a depth of 2 to 3 inches in a Dutch oven; heat to 375 degrees F.

Fry 2 or 3 doughnuts at a time 1 minute on each side or until golden brown. Drain well on paper towels. Sprinkle with confectioners' sugar, and serve immediately.