Preheat your oven to 325°F. Spray three 8-inch cake pans with nonstick spray, line with parchment paper, and spray again. Set aside.

In a medium bowl, whisk together the flour, baking powder, baking soda, and salt.

In another medium bowl, mash the bananas with a fork until completely smooth.

In the bowl of a stand mixer fitted with the paddle attachment, beat the butter, oil, and sugar on medium-high speed until light and fluffy, about 5 minutes.

Reduce speed to medium and add the eggs one at a time, mixing for about 30 seconds between each addition. Add the vanilla and mix on low until combined.

Scrape down the sides and bottom of the bowl.

With the mixer on low, alternate adding the dry ingredients and buttermilk in three parts, beginning and ending with the dry. Mix until just combined.

Fold in the mashed bananas by hand using a rubber spatula, making sure to scrape the bottom of the bowl.
Tip: Don’t overmix once the flour is added—just fold gently until no flour streaks remain.

Divide the batter evenly between the three pans (use a kitchen scale for accuracy). Smooth the tops with a small offset spatula.

Bake for 28–32 minutes or until a toothpick inserted in the center comes out clean or with a few moist crumbs.

Let cakes cool in pans on a wire rack for 10 minutes, then remove from pans and let cool completely.
Pro tip: If the cake domed while baking, level the tops with a serrated knife once cooled for easy stacking.

In a medium heavy-bottomed saucepan, combine the sugar, water, and corn syrup. Gently stir to moisten all the sugar, then stop stirring.

Set the pan over medium heat and cook undisturbed for 5–10 minutes, until the mixture turns deep amber.

Meanwhile, warm the heavy cream in the microwave for about 1 minute.

Once the caramel is a rich copper color, remove from heat and carefully pour in the warm cream.
Caution: The mixture will bubble up rapidly. Pour slowly and whisk constantly.

Whisk until smooth. Stir in the vanilla, salt, and butter. Return to low heat briefly if needed to smooth it out.

Let cool slightly, then transfer to a heat-safe jar and refrigerate until ready to assemble.
The caramel will thicken as it cools.

In a medium saucepan, melt 1½ cups (3 sticks) of unsalted butter over medium heat. Continue cooking, swirling the pan occasionally, until the butter foams and turns a deep amber color with a nutty aroma — about 5–7 minutes.

Immediately transfer the browned butter to a large heatproof bowl and stir in ½ cup (1 stick) of unsalted butter until fully melted and incorporated. This helps rehydrate the browned butter and improve the frosting’s consistency.

Let the butter cool to room temperature (about 2 hours) before using.

When ready to frost, place the room temperature browned butter and cream cheese into the bowl of a stand mixer fitted with the paddle attachment. Beat on medium-high speed for 2–4 minutes until light and fluffy.

Add the powdered sugar, heavy cream, vanilla, and salt. Mix on low to combine, then beat on high for 2 more minutes.

Use a rubber spatula or wooden spoon to beat out any air pockets before frosting.

Place a small dollop of frosting in the center of a cake board to act as glue.

Add the first cake layer top-side up. Spread about 1 cup of frosting over the top and drizzle with caramel sauce.

Add the second cake layer top-side down and repeat the frosting and caramel.

Add the final cake layer top-side down again.

Apply a thin crumb coat of frosting and chill the cake for 15 minutes.

Frost the entire cake with the remaining brown butter frosting. Add a caramel drip if desired and serve extra caramel on the side.
This cake is best served at room temperature for the perfect texture and flavor. I highly recommend it.