Heat oven to 350 degrees F. Lightly butter and flour a 12-cup bundt pan, shaking out excess flour. Set aside.
Combine butter and sugar in the bowl of a standing mixer. Cream, using paddle attachment, until light and fluffy. Add eggs, one at a time, mixing well and scraping the bowl after each addition. Add vanilla and orange zest. Mix well.
Combine 2-1/2 cups of the flour, salt and baking powder on a large sheet of waxed paper. Add half to butter mixture in bowl, then the sour cream, then remaining flour mixture, beating until smooth. Toss cranberries with remaining 1 tablespoon flour, then fold into batter.
Pour into prepared pan. Bake at 350 degrees F for 45 minutes. Reduce temperature to 325 degrees F and bake 20 minutes, or until a skewer inserted in the center comes out clean. Remove to a wire rack to cool.
Garnish and Glaze:
Place beaten egg white in a small bowl. Dip cranberries and orange peel in egg white, then in granulated sugar. Let dry on a plate. In a medium-size bowl, blend confectioners' sugar and 2 tablespoons water until smooth (adding more water if too thick). Spoon over cake, allowing to drip down sides. Arrange sugared peel over cake (do not eat garnish, as consuming raw egg whites is not recommended).