Mardi Gras King's Cake

INGREDIENTS:
1/2 cup water, (105 to 115 degrees)
2 envelopes active dry yeast
3 1/2 to 4 1/2 cups all-purpose flour
1/2 cup granulated sugar
1/2 teaspoon nutmeg, freshly grated
2 teaspoons salt
1 teaspoon lemon rind, grated
1/2 cup water, lukewarm
3 eggs
4 egg yolks
1/2 cup butter, softened
1 egg, lightly beaten with
1 teaspoon of milk
1 small doll, coin, or bean
3 cups confectioners sugar
1/4 cup lemon juice, strained
3 teaspoons water or more
green, purple, and yellow sugars
PREPARATION:
Dissolve yeast in water; let stand for about 5 to 10 minutes. Combine flour, sugar, nutmeg, salt and lemon rind in a large bowl. Make a well in center. Add yeast mixture, milk, eggs, egg yolks and combine completely.

Beat in butter until dough forms a ball. Place on floured board; incorporate more flour if necessary. Knead until smooth and elastic. Stir dough in well buttered bowl and turn so all surfaces are buttered. Cover with a towel and let rise 1 1/2 hours or until doubled in bulk. Brush baking sheet in butter. Punch down on lightly floured board. Knead, then pat into a 14" cylinder. Place on baking sheet and form into a large ring. Press doll or coin into dough so that it is well hidden. Set aside, covered with a towel, to rise 1 to 1 1/2 hours. Before baking, brush top with the egg milk mixture. Bake in a preheated 375° oven for 25 to 30 minutes, or until golden brown. Cool on wire rack. Beat icing ingredients until smooth. Spread over top of cake, letting drip down sides.
Immediately sprinkle sugars over icing in 2" wide strips of purple, green and yellow stripes. *Colored sugar is sold in baking supply houses. If you can't find it, tint granulated sugar or icing with paste food coloring. Be sure to tell people about the hidden doll or bean if they aren't familiar with the tradition