Step 1

Preheat oven to 350°F. Grease or lightly spray a 9 x 13 inch cake pan with nonstick spray.

Step 2

Whisk together flour, sugar, baking powder, baking soda, and salt in a large bowl.

Step 3

Add mashed bananas, buttermilk, shortening, eggs, and vanilla to the bowl. With an electric mixer, beat on low-speed until ingredients are combined, scraping sides of bowl as needed, about 1 minute.

Step 4

Increase to medium speed and beat for 3 minutes. Fold in chocolate chips.

Step 5

Spread cake batter into prepared pan and bake for 30 to 35 minutes or until a toothpick inserted into center of cake comes out clean or with crumbs.

Step 6

Cool completely before frosting.

Step 7

In large bowl, using an electric mixer, beat together cream cheese, butter, vanilla, and milk until smooth.

Step 8

Add cocoa powder and powdered sugar (one cup at a time) and continue to beat on low speed until frosting is smooth and is desired consistency. Spread on cooled cake.