Sherbet-Filled Angel Food Cake

Directions

1. 1

   Place egg whites in a large bowl; let stand at room temperature 30 minutes.
2. 2

   Preheat oven to 325°. In a small bowl, mix flour and 3/4 cup sugar until blended.
3. 3

   Add seeds from vanilla bean (or extract if using), cream of tartar and salt to egg whites. Beat on medium speed until soft peaks form. Gradually add remaining 3/4 cup sugar, 1 tablespoon at a time, beating on high after each addition until sugar is dissolved. Continue beating until soft glossy peaks form. Gradually fold in flour mixture, about 1/2 cup at a time.
4. 4

   Gently transfer batter to an ungreased 10-in. tube pan. Cut through batter with a knife to remove air pockets. Bake on lowest oven rack 45-55 minutes or until top springs back when lightly touched. Immediately invert pan; cool completely in pan, about 1-1/2 hours.
5. 5

   Run a knife around sides and center tube of pan. Remove cake to a serving plate. Using a serrated knife, cut a 1-in. slice off top of cake. Hollow out remaining cake, leaving a 1-in.-thick shell (save removed cake for another use). Fill tunnel with sherbet, mounding slightly; replace cake top. Wrap cake securely in plastic; freeze overnight.
6. 6

   To serve, in a small bowl, mix confectioners' sugar, lime zest and enough lime juice to reach desired consistency. Unwrap cake; spread glaze over top, allowing some to drip down sides. Freeze until serving.