Caramelized Banana Crème Brulee Cupcakes

From 6 Bittersweets
Adapted from How to Eat a Cupcake via Beantown Baker
Make 12 cupcakes

1 1/4 cups all purpose flour
1 1/2 teaspoons baking powder
1/4 teaspoon salt, plus a pinch for the egg whites
1/4 cup (1/2 stick) unsalted butter, room temperature
1/2 cup sugar
1/2 teaspoon molasses (not blackstrap)
(You can simply use 1/2 cup of brown sugar instead of the sugar and molasses)
1 egg, separated
2/3 cup milk
1/2 cup sweetened condensed milk
1 teaspoon vanilla extract

Caramelized Banana Filling (Recipe below)
Brown Sugar Swiss Meringue Buttercream (Recipe below)
1/3 cup granulated sugar (for torching...mwahaha)

Preheat oven to 350°F. Line a muffin pan with 12 cupcake liners. Sift flour, baking powder, and salt together and set aside. Cream butter and sugar together until light and fluffy. Add egg yolk and mix in well. Add molasses and vanilla. Beat until smooth. Alternately beat in dry ingredients and milks.

In a separate (completely grease-free) bowl, beat the egg white with a pinch of salt until stiff but not dry. Gently fold whites into batter.

Spoon batter into cupcake papers (I like to use my large cookie scoop for this), filling cups about 2/3 full. Rap the pan against the counter once to get rid of any air bubbles. Bake for about 15-20 minutes or until a toothpick inserted into the center comes out clean. Remove from oven and cool completely.

Cut a cone out of each cupcake. (You won't be needing the tops anymore so feel free to nom on them. You deserve it, cupcaking is hard work!) Spoon in 1-2 pieces of the caramelized banana filling into each cupcake, then spread or pipe buttercream on top.
Sprinkle sugar over the frosting and caramelize with a creme brulee torch. (Be careful to hold the torch no closer or longer than necessary, to avoid melting the buttercream.) Top cupcakes with a piece of caramelized banana each if you want folks to know what's inside (BUT you gotta chill the cupcakes at least 30 minutes after torching OR all that precious buttercream will avalanche, as pictured above). Or just let it be a delicious surprise =D.

Caramelized Banana Filling
Adapted from Recipezaar

XIAOLU'S NOTE: My bananas turned gray overnight. I found out that you can use the juice of any citrus fruit, such as lime, lemon, grapefruit, or orange, will prevent discoloration.

2-3 firm, ripe bananas
4-6 tablespoons sugar
2 tablespoons butter
2 tablespoons dark rum, optional
juice of any citrus fruit
Slice bananas into 1/2"-thick coins. Sprinkle slices with citrus fruit juice to prevent discoloration.

Melt butter in medium size nonstick pan over medium-high heat. Sprinkle sugar evenly over the melted butter, then add the bananas in a single layer on top of the sugar. Cook bananas until light to golden brown underneath, about 4-5 minutes (you can lift with a spatula to peak). Be careful not to overcook or burn them (if you smell them browning, or see color in the pan, flip them right away). Sprinkle rum, if using, over the bananas. When cooking with alcohol, there is always the chance of it catching on fire, so be very careful when adding the rum. Gently flip bananas over to brown the other side, turning heat down to medium. The second side will brown in about one minute.

Transfer to a plate that has been coated with oil or cooking spray (otherwise they may stick) and set aside. Soak pan in hot water to make cleaning easier later on. Or you can fill it with water and reheat it over medium heat to dissolve any stubborn bits.

Brown Sugar Swiss Meringue Buttercream

XIAOLU'S NOTE: My buttercream remained soupy even after 8+ minutes of beating. I guessed that my beater blade, the temperature, or the amount of butter was the problem. So I chilled the mixer bowl for 10 minutes, switched to the paddle attachment, and added 3 more tablespoons of cold butter, 1 tablespoon at a time. The buttercream came together in under 3 minutes of mixing this time, at which point I may have let out a celebratory yelp.

1/2 cup light brown sugar
2 egg whites
1/8 teaspoon salt
1/2 cup (1 stick) unsalted butter, cooler side of room temperature
1 teaspoon vanilla extract

Combine sugar, egg whites, and salt in the mixing bowl of your stand mixer over a pan of simmering water. Whisking constantly, cook until sugar has dissolved and mixture is warm (about 160 degrees). Turn off the stove and move the bowl to your stand mixer fitted with the whisk attachment. Beat egg white mixture on high speed until it forms stiff (but not dry) peaks. Continue beating until fluffy and cooled (this is important), about 7 minutes total.

Switch to the paddle attachment. With mixer on medium-low, add butter two tablespoons at a time, beating well after each addition (about 10 seconds between each addition). Increase speed to medium-high; continue beating until frosting appears thick, at least 3 minutes. (You'll hear a distinct slapping sound and visibly see the buttercream go from soupy to cohesive when it becomes SMBC.) Reduce speed to low, add the vanilla, and continue beating 1 minute to incorporate the extract and reduce air bubbles.