Dissolve yeast in milk; let stand 5 minutes. Soften 1/2 cup butter in a large mixing bowl; beat until smooth. Gradually add 1/2 cup sugar, beating until light and fluffy. Add eggs, beating well. Add flour and yeast mixture alternately, beginning and ending with flour, stirring well after each addition.
Turn dough out onto a lightly floured surface; knead 5 minutes or until smooth. Place in a greased bowl, turning to grease top. Cover and let rise in a warm place (85°), free from drafts, 1 hour or until doubled in bulk.
Turn dough out onto a lightly floured pastry cloth. Roll into a 23- x 13-inch rectangle. Melt remaining butter; brush on rectangle. Sprinkle with remaining sugar and candied fruit. Roll up jellyroll fashion, beginning at long side; moisten edges to seal.
Pour Rum-Butter Mixture into a well-greased 10-inch tube pan; arrange roll over mixture. Pinch ends together to seal. Cover; repeat rising procedure.
Bake at 350° for 50 minutes. Remove from oven; invert pan, and cool cake. Slice and serve.