Preheat oven to 350 degrees Fahrenheit. Grease a bundt cake pan with shortening, then dust with flour.
In a large bowl, prepare the yellow cake mix according to the directions on the box. Set aside.
In a small bowl, mash the bananas, cinnamon (which is optional) and baking soda up until it’s nice and creamy. Add the banana mixture to the cake mix mixture and blend until well combined.
Pour the batter into your prepared pan and bake for 40-50 minutes, test with a toothpick for doneness.
Allow the cake to cool for 10 minutes on the plate, then turn it out onto a plate to cool completely.
Make the glaze:
Cream together the cream cheese and butter until well combined.
Add in the vanilla extract and slowly add in the powdered sugar mixing well with each addition. Slowly add in the milk and mix until a nice drizzle has been reached and all of the lumps are gone.
Pour the glaze over your cooled cake.
Top with crushed walnuts.
Store in an airtight container.
The calories shown are based on the cake being cut into 15 pieces, with 1 serving being 1 slice of cake. Since different brands of ingredients have different nutritional information, the calories shown are just an estimate. **We are not dietitians and recommend you seek a nutritionist for exact nutritional information.**