In a large bowl, combine the flour, sugar, baking powder, baking soda and salt. In a small bowl, whisk the butter, sour cream, eggs, orange juice and orange peel. Stir into dry ingredients just until moistened.
Coat a 9-inch springform pan with shortening and sprinkle with flour. Spread half the batter into prepared pan. Add rhubarb to within 1/2 inch of the edges. Sprinkle with cinnamon and allspice. Top with remaining batter.
For Streusel: Combine the flour, sugar and cinnamon in a small bowl; cut in butter until crumbly. Sprinkle over batter. Bake at 350º degrees for 35 to 45 minutes or until a toothpick inserted near the center comes out clean. Cool for 10 minutes.
For glaze: In a small bowl combine confectioners' sugar and orange juice. Drizzle over warm cake. Cool for 1 hour.