Combine 2 cups of flour, yeast, sugar, salt and spices in a large mixing bowl. In a separate bowl, heat milk and butter to very warm (120 to 130ø). Add to flour. Beat on medium speed of mixer for 1 minute. Add eggs. Beat another minute. Stir in currants, orange peel and enough remaining flour to make dough easy to handle. Turn dough out onto lightly floured surface and knead until smooth and elastic, about 5 minutes, adding additional flour as needed. Place in a buttered bowl, turning to butter top. Cover; let rise in warm place until doubled in bulk, about 1 hour. Punch down dough; turn onto lightly floured surface. Divide dough in half; divide each half into 9 pieces. Form each piece into a smooth round ball. Place balls of dough in two buttered 8-inch square baking pans. Cover; let rise in warm place until doubled in bulk, about 45 minutes to 1 hour. Brush lightly with egg yolk mixture. Bake rolls in preheated 375 degree oven, 20 to 25 minutes, or until golden brown. Remove from pans. Cool on wire rack.. Drizzle frosting across the top of each bun in the shape of a cross. Makes 18 buns.