Soak raisins in rum for at least 30 or overnight.
Combine 1/2 teaspoon sugar along with yeast and water in small bowl. Let stand until foamy, about 5 minutes.
Beat together remaining sugar, butter, eggs, vanilla, powdered milk, salt and saffron, if using, and yeast mixture in large bowl with mixer until blended. Add 2 cups of the flour and 1 tablespoon of soaking rum, beating for 2 minutes at high speed.
Drain raisins and reserve rum for glaze. Stir raisins, almonds and orange peel into dough with wooden spoon. Stir in enough of remaining flour to form a soft dough. Turn out onto floured surface and knead until smooth and elastic, about 5 minutes.
Place dough in greased bowl, turning to coat. Cover; let rise in warm spot for 1 1/2-2 hours, until doubled. Grease well two 1 lb. coffee cans. Line bottoms with rounds of waxed paper.
Turn dough out onto floured surface. Punch down; knead a few turns. Divide in half and place in prepared cans. (They should be about two-thirds full.) Let rise, covered, for about 1 1/2 hours, or until it has risen to top of can.
Preheat oven to moderate (350'F). Brush tops of breads lightly with water.
Bake in lower third of preheated moderate over (350'F) for 35-40 minutes or until golden brown on top and long skewer inserted in center comes out clean. Check after 25 minutes and tent with foil if browning too quickly.
Using oven mitts, carefully remove the bread from the cans, supporting top of bread and twisting off can. Cool upright on wire rack to room temperature. Drizzle glaze over breads. Garnish with candied orange peel and slivered almonds, if you wish.
SUGAR GLAZE: Stir together confectioners' sugar, reserved soaking rum, lemon juice and water as need, in small bowl until good drizzling consistency.