1Heat oven to 350°F (325°F for dark or nonstick pan). Grease and lightly flour 12-cup fluted tube cake pan, or spray with cooking spray.
2In large bowl, beat cake mix, water, bananas, butter, cinnamon and eggs with electric mixer on low speed 30 seconds, then on medium speed 2 minutes, scraping bowl occasionally. Stir in walnuts. Pour into pan.
3Bake 47 to 57 minutes or until toothpick inserted in center comes out clean. Cool in pan 10 minutes. Turn pan upside down onto cooling rack or heatproof serving plate; remove pan. Cool completely, about 2 hours. In small bowl, stir glaze ingredients until thin enough to drizzle. Drizzle over cake. Store loosely covered.