Heat oven to 325°F. Grease 1 (1 1/2-quart) ovenproof bowl (8 inches across top) and 2 (8-inch) round cake pans with shortening; coat with flour (do not use cooking spray).*
In large bowl, make both cake mixes as directed on box, using water, oil and eggs for each mix. (Two boxes of cake mix can be made at one time; do not make more than 2 boxes, and do not increase beating time.) Pour 3 1/2 cups batter into 1 1/2-quart bowl and 2 1/4 cups batter into each cake pan.
Bake cake pans 35 to 40 minutes and bowl 45 to 50 minutes or until toothpick inserted in center comes out clean. Cool 10 minutes. Remove cakes from pans and bowl; place rounded sides up on cooling racks. Cool completely, about 1 hour. If necessary, cut off rounded tops of cakes baked in 8-inch pans. Cut 2-inch-diameter hole in center of all 3 cakes.
Spoon frosting into large bowl. Stir in enough food color until desired pink color. Place one 8-inch cake on serving plate; spread 1/3 cup frosting over top. Top with second 8-inch cake; spread with 1/3 cup frosting. Top with bowl cake.
Wrap hair and lower half of doll with plastic wrap. Insert doll into center of cake. Trim side of cake if necessary to make a tapered "skirt."
To "crumb-coat" cake, spread thin layer of frosting over side and top of layered cake to seal in crumbs. Freeze cake 30 to 60 minutes.
Fit #24 star tip into decorating bag. Spoon 1/4 cup pink frosting into decorating bag; set aside. Starting at waist of doll, frost cake with downward strokes to make ruffled skirt. Use star tip to cover bodice of doll and add decoration to skirt if desired. Gently press star decors into frosting to decorate neckline and skirt. Unwrap hair.
*As shown in How-To Video, cake can be baked in 3 (8-inch) round cake pans and 1 (1 1/2-quart) bowl. Use 3 1/2 cups batter in bowl and 1 2/3 cups batter in each cake pan. Bake cake pans 30 to 35 minutes and bowl 45 to 50 minutes.