Preheat oven to 350°F. Beat cake mix, dry pudding mix, eggs, sour cream, dressing, sherry and poppy seed with electric mixer on medium speed until well blended. Pour into greased and floured 12-cup fluted tube pan or 10-inch tube pan.
Bake 50 minutes or until toothpick inserted in center comes out clean. Cool 10 minutes; remove from pan. Cool completely on wire rack.
Mix powdered sugar, milk, orange juice, butter and orange peel until smooth; drizzle over cake. Store in airtight container at room temperature.