My Grandma Bonnie Made These Banana Bars Every Winter (They’re My Favorite)

My Grandma Bonnie loved to bake, and we all loved eating her treats. Before we grandkids came along, she cooked multiple meals for her family and any farmhands working on their farm in Iowa at the time. When they moved to town and her kids started having children, her baking legacy continued. 

During the winter, when we visited my grandparents for the holidays, my grandma made so many desserts that my grandpa had to clear a whole shelf in the garage to store them all and keep them cold. There was always a variety of homemade bars, cookies, and candies—anything you could think of. It was also out of the eyesight of the adults, allowing us kids to sneak out and grab whatever we wanted, whenever we wanted. 

Among those treats were my favorites: Grandma’s banana bars. This dessert consists of a moist, thin, cake-like bar with cream cheese frosting, sprinkled with toasted nuts. Similar to a thin banana bread or snack cake, they are wonderful to eat throughout the day.

While her version was creamed together using a mixer, I simplified it so it doesn’t require any special equipment and can be prepared all in one bowl (except for the cream cheese frosting). Mashed bananas and sour cream make them tender and moist.

Bake in a Sheet Pan—or Change It Up!

My Grandma Bonnie’s original recipe calls for an old-fashioned jelly roll pan, but since many folks don’t have one at home, I adapted it to work in a standard 13×18-inch baking sheet (technically a “half-sheet” pan). Baked this way, the recipe will make about 36 slices—great for serving a crowd.

That said, if you happen to have a 10×15-inch jelly roll pan, feel free to use it! The baking time will need to increase to about 25 minutes. Made this way, the bars will be a little thicker and will yield 30 bigger bars or 36 smaller ones.

If you don’t want to make quite as many, you can cut this recipe in half and bake in a 9×13-inch baking pan.

Tips for Making These Banana Bars

• Don’t overbake them: While these bars are incredibly moist, they are also cake-like and quite thin; be sure not to overbake them. They can quickly dry out if left too long in the oven. Bake just until a toothpick inserted in the center comes out clean.
• Serve them from the pan: These bars are thin and moist and best served straight from the pan. Slice them into squares with a thin, sharp knife and use a thin, flexible spatula to remove each slice.
• Switch up the flavors: I have also swapped out the 1 cup of mashed bananas in this recipe for 1 cup of pumpkin purée to make pumpkin bars instead of banana bars, and they’re so good! I add a dash of pumpkin pie spice, too.