Good-Cooking - Banana Pudding Bundt Cake

Ingredients

• 1 (18.25 ounce) box yellow cake mix
• 1 (3 ounce) box instant banana pudding mix
• 4 eggs
• 1 cup water
• 1/4 cup vegetable oil
• 3/4 cup mashed banana
• 2 cups confectioners' sugar
• 2 tablespoons milk
• 1 teaspoon vanilla extract
• 1/2 cup walnuts, finely chopped