Carrot-Walnut Bundt Cake with Lemon Cream Cheese Icing

Place rack in center of oven and preheat to 350°F. Butter 12-cup nonstick Bundt pan. Whisk flour, cinnamon, baking soda and salt in medium bowl until well blended. Using electric mixer, beat sugar, oil and eggs in large bowl on medium speed until pale and fluffy, about 5 minutes. Add flour mixture, beating just until blended. Fold in carrots and walnuts. Pour batter into prepared pan. Bake cake until toothpick inserted near center comes out clean, about 50 minutes. Cool cake in pan on rack 1 hour. Invert cake onto plate. Cool completely. Drizzle icing over top of cake, allowing icing to flow down sides. (Can be made 1 day ahead. Cover and chill.)