From A Taste of Our State series. Click here to read or listen to contributor Sheri Castle’s column from the June 2026 issue.

Many of us are familiar with the vintage chocolate cake recipe that calls for mayonnaise. It sounds suspect, but when you consider that the main ingredients in mayonnaise are oil and eggs, things found in most cakes, it makes more sense. No one could possibly guess that’s what makes the cake so moist and tender, which made me curious whether mayo magic would work in other cakes. I grew up eating banana-and-mayo and banana-and-peanut butter sandwiches and enjoy both to this day. A few years ago, I learned that some people put all three of those things on one sandwich. That combination is the inspiration for this snack cake. Plus, people who love eating peanut butter straight from the jar will adore this frosting.

For the cake:
1 cup mashed bananas (2 to 3 very ripe bananas)
1 cup mayonnaise (not reduced fat)
1 cup granulated sugar
⅓ cup water
1 teaspoon vanilla
2 cups all-purpose flour
½ teaspoon baking powder
½ teaspoon baking soda
½ teaspoon kosher salt
½ teaspoon cinnamon

For the frosting:
1 cup creamy peanut butter (not the type that separates and must be stirred)
⅓ cup heavy cream
5 tablespoons unsalted butter, softened
¼ teaspoon kosher salt
1 teaspoon vanilla
1 cup powdered sugar, sifted

For the cake: Position a rack in the center of the oven and preheat to 350º. Mist a 9-inch round cake pan with nonstick spray. Line the bottom with a round of parchment paper and mist the paper.

In a large bowl using a spatula, stir together bananas, mayonnaise, sugar, water, and vanilla.

In a separate bowl, whisk together flour, baking powder, baking soda, salt, and cinnamon.

Add flour mixture to banana mixture; whisk until dry ingredients are just incorporated.

Scrape batter into prepared pan. Bake on center rack until a tester inserted into the middle of the cake comes out clean, about 50 minutes. Let cool in pan on a wire rack for 10 minutes. Remove cake from pan and place topside up on wire rack to cool completely before frosting.

For the frosting: In a medium bowl using a mixer on low speed, beat peanut butter, cream, butter, salt, and vanilla until smooth. Add powdered sugar and beat on low until smooth, scraping the bowl as needed. Use immediately or store in an airtight container in the refrigerator for up to 5 days. Return to room temperature and stir well before using.