Preheat the oven to 325°F (163°C). Prepare three 8-inch cake pans (or four 6-inch pans) by spraying them with nonstick spray, lining the bottoms with parchment paper, and spraying again. Set aside.

In a medium bowl, whisk together the flour, baking powder, and salt until well combined, then set aside.

In the bowl of a stand mixer fitted with the paddle attachment, beat the butter and sugar on medium-high speed for 3 to 5 minutes, until the mixture is light and fluffy.

Add the eggs one at a time, mixing well after each addition and scraping down the sides and bottom of the bowl to ensure everything is fully incorporated. Add the vanilla extract.

With the mixer still on medium-high speed, add the dulce de leche and mix for another couple of minutes until the mixture becomes slightly lighter in color.

Reduce the speed to low and alternate adding the dry ingredients and the milk, beginning and ending with the dry mixture. Mix until just combined.

Gently fold in the honeycomb pieces by hand. Note: the honeycomb will melt and caramelize as it bakes, creating pockets of flavor and small craters in the cake. Don’t worry—these will be filled with buttercream and add delicious texture.

Divide the batter evenly between the prepared pans and bake for 30 to 35 minutes, or until a toothpick inserted in the center comes out with just a few moist crumbs.

Allow the cakes to cool in their pans on a wire rack for 10 to 15 minutes, then invert them onto wire racks (tip: spray the racks with nonstick spray) to cool completely.

The cakes can be made in advance, wrapped tightly in plastic wrap, and frozen. When ready to use, let them sit at room temperature for 30 to 60 minutes before stacking and decorating.

In a small saucepan, combine the granulated sugar, water, and corn syrup.

Bring the mixture to a boil over medium heat, without stirring. Stirring can cause the sugar to crystallize. Let the mixture cook undisturbed until it turns a deep golden-brown or nearly bronze color. This process happens quickly once it begins, so keep a close eye on it.

Remove the saucepan from heat and carefully pour in the cream, just a little at a time at first, stirring constantly. As the bubbling settles, gradually add the remaining cream.

Add the vanilla and salt, then stir to fully combine.

Set the caramel sauce aside and allow it to cool completely before using it in the frosting.

Once fully cooled, divide the caramel sauce in half—use one half for the frosting and save the other half to drizzle on the cake.

To make the buttercream, beat the butter, sifted powdered sugar, and the reserved half of the caramel sauce in a stand mixer fitted with the paddle attachment until smooth and fluffy. If the frosting is too thick, add a small amount of cream until it reaches your desired consistency.

Place the first cake layer onto a cake board or serving plate. Spread approximately 1 cup of the buttercream evenly over the top using an offset spatula. Drizzle a few tablespoons of caramel sauce over the buttercream.

Break 1/2 to 1 cup of honeycomb into small chunks and sprinkle them over the buttercream and caramel. Gently press them into the surface to secure.

Add the second cake layer and repeat the same process—buttercream, caramel drizzle, and honeycomb pieces.

Place the final cake layer on top, this time with the flat (bottom) side facing up.

Apply a thin crumb coat of buttercream over the entire cake and place it in the freezer for 10 to 15 minutes to set.

Once the crumb coat is firm, apply the remaining buttercream evenly around the cake. Finish by drizzling the remaining caramel sauce over the edges to create a drip effect. Garnish the top with additional honeycomb pieces.