Chocolate-Strawberry-Orange Wedding Cake

Position 1 rack in center and 1 rack in bottom third of oven and preheat to 350 °F. Butter one 5-inch-diameter cake pan with 2-inch-high sides, one 8-inch-diameter cake pan with 2-inch-high sides and one 12-inch-diameter cake pan with 2-inch-high sides. Dust pans with flour; line bottoms with parchment. Combine 1/3 cup orange juice and 2 ounces unsweetened chocolate in heavy small saucepan. Stir mixture over medium-low heat until chocolate melts. Remove from heat. Gradually mix in 1 2/3 cups orange juice. Sift 3 cups flour, 2/3 cup cocoa, 2 teaspoons baking soda, 1 teaspoon salt and 1/2 teaspoon baking powder into medium bowl. using electric mixer, beat 1 cup (2 sticks) butter and 3 cups sugar in large bowl until blended (mixture will look grainy). Add 4 eggs, 1 at a time, beating to blend after each. Beat in 1 tablespoon orange peel and 1 tablespoon vanilla extract. Add dry ingredients alternately with orange juice mixture in 3 additions each, beating well after each addition. Mix in 1 cup chocolate chips. Transfer 1 cup plus 2 tablespoons batter to prepared 5-inch pan, 3 cups batter to prepared 8-inch pan and remaining batter (about 6 cups) to 12-inch pan. Place 5-inch and 8-inch pans on center rack of oven. Place 12-inch pan on lower rack of oven. Bake cakes until tester inserted into center comes out clean, about 35 minutes. Transfer cakes in pans to racks and cool completely. Mark 4-inch diameter circle on one 6-inch-diameter cardboard cake round. Cut out marked circle. Mark 7-inch-diameter circle on one 8-inch-diameter cardboard cake round. Cut out marked circle. Mark 11-inch-diameter circle on one 12-inch-diameter cardboard cake round. Cut out marked circle. Cut around sides of 5-inch-cake to loosen. Place 4-inch cardboard over pan. Hold cardboard and pan together; turn cake out onto cardboard. Peel off parchment. Wrap cakes on its cardboard in foil. Repeat turning out, peeling off parchment and wrapping cakes in foil, using 7-inch cardboard for 8-inch cake and 11-inch cardboard for 12-inch cake. Using remaining ingredients, make 1 more batch of cake batter and bake 3 more cake layers as described above. Cool cakes in pans. Cover cakes in pans tightly with foil. (Can be prepared ahead. Let stand at room temperature up to 1 day or double-wrap all cake layers and freeze up to 1 week. Bring cake layers to room temperature before using.)