Preheat your oven to 350°F and grease two 9-inch round cake pans. Line the bottoms with parchment paper for easy removal.

In a medium mixing bowl, whisk together the flour, baking powder, and salt. Set aside.

In a large mixing bowl, whisk the melted butter, eggs, milk, and vanilla until fully combined.

Gradually add the dry ingredients to the wet ingredients, stirring gently until the batter is smooth and well incorporated.

Divide the batter evenly between the prepared cake pans and bake for 45 minutes, or until a toothpick inserted in the center comes out clean.

Let the cakes cool in the pans for 10 minutes, then turn them out onto a wire rack to cool completely before assembling. (Around 1 hour)

In a large mixing bowl, combine the heavy whipping cream, powdered sugar, and vanilla extract.

Using an electric mixer, beat on high speed until stiff peaks form. Set aside in the fridge until ready to assemble.

In a heatproof mixing bowl, whisk together the egg whites and granulated sugar.

Place the bowl over a pot of simmering water, making sure the bottom of the bowl doesn’t touch the water. Whisk constantly until the sugar dissolves and the mixture is warm to the touch.

Remove from heat and use an electric mixer to beat the mixture on high speed until thick, glossy, and stiff peaks form. Beat in the vanilla extract and set aside.

Once the cakes are completely cool, use a sharp knife to carefully slice each cake in half horizontally, creating four layers.

Place one cake layer on a serving plate and spread a layer of whipped cream over the top. Arrange a layer of sliced bananas on top of the whipped cream.

Repeat this process with the next two layers, stacking them with whipped cream and banana slices.

Top with the final cake layer and spread a thin layer of whipped cream over the entire outside of the cake for a "naked cake" look.

Spoon the marshmallow fluff over the top of the cake, spreading it evenly to cover the surface.

Using a small spoon, create swirls in the marshmallow fluff for a beautiful finish.

Using a pastry torch, carefully toast the marshmallow fluff until golden brown. (Be careful not the melt the whipped cream under the marshmallow)

Slice and serve immediately, or refrigerate until ready to enjoy!