Begin with making the dulce de leche. Boil sweetened
condensed milk cans for 4 hours in the sealed can. During this process the
water will evaporate several times, be sure to keep refilling the water so the
can stays submerged throughout the cooking process.
Preheat oven to 375 degrees F.
To make the banana cupcakes, cream butter, oil and sugar in
a stand mixer fitted with a paddle attachment. Add in egg then egg whites, one
at a time until mixed. Scrape down the sides as needed.
Combine cake flour, baking powder, and salt in a separate bowl.
Whisk to combine and then add to the stand mixer. Add vanilla and mashed banana
last.
Line muffin tins with liners. Scoop or spoon batter to ¾ of
the way full. Bake for 18-20 minutes.
Once baked, take a large flat piping tip and remove the core
of the banana cupcake while it’s still warm.
Once cupcakes have fully cooled, fill the banana cupcakes
with about 1 tsp of dulce de leche. Place the dulce de leche in a piping back to
easily pipe into the cupcakes.
To make the marshmallow meringue, place a saucepot with an inch
full of water on high. Place whites in a comparable size metal mixing bowl and
place over the top of the sauce pot, creating a double boiler. Add in sugar slowly
while whisking, so that the sugar fully dissolves into the whites. Continue to
do so until the sugar is fully dissolved and no grains are left.
Transfer the whites to a mixer fitted with a whisk
attachment and beat on high until you reach stiff peaks. Add vanilla and whisk
until combined.
Transfer mixture to a piping bag fitted with a large flat
tip and pipe meringue onto cupcakes.Lightly torch the top. Serve and enjoy!