Pre-heat oven to 350F. Line a 12-cupcake pan with cupcake liners or grease it with butter and flour.

Sift flour, cocoa powder, sugar, baking soda, baking powder, espresso powder, and salt together in a large bowl.

In another bowl, mix coffee, vinegar, vanilla and oil. Pour dry mixture over wet ingredients. Whisk briefly, until incorporated. Be careful not to overmix. As soon as you see no more streaks of dry mixture, stop whisking.

Distribute batter evenly in cupcake pans.

Bake for 15-20 minutes.

Remove and let it cool.

Mix all ingredients except for the chopped chocolate, and vanilla in a small saucepan. Bring it to a boil over medium heat.

Simmer on low for 5 minutes, stirring constantly.

Remove form the heat, add chocolate and stir until melted together.

Add vanilla.

Let it cool down to room temperature before using. It will need to have the perfect consistency in order to drip perfectly on top of the cupcakes. It can’t be too cold, or too hot. It needs to be just at room temperature.

Cream butter in the bowl of a mixer, at medium-high speed for 2 minutes.

Turn mixer off. Add sugar. Mix on low until sugar is incorporated.

Cream for another 1 minute.

Add vanilla and mix to combine. If texture is too stiff, add the heavy cream. Otherwise, it’s ready to pipe.

Prepare your equipment: Line a 8x8” cake pan with parchment paper, and brush the parchment paper with neutral oil.

You will also need a scraper or spatula, brushed with neutral oil as well, when it’s time to remove the marshmallow from the bowl to the pan.

Sift powdered sugar and cornstarch together in a bowl. I like to use one of those shakers that have the perforated top, to make it easier to sprinkle the powder over marshmallows to coat evenly and delicately.

Place sugar, agave syrup, and 1/3 cup of water in a saucepan.

Stir until combined.

Use a brush dipped in water to clean the sides of the saucepan from any sugar granules.

Place a candy thermometer in the pan.

Over medium heat, let mixture come to a boil. Gently swirl the pan while turning the heat down to medium-low.

Let mixture cook until the temperature reaches 245F.

While syrup cooks, place gelatin and 1/2 cup of water in the bowl of a stand mixer. Stir to combine and let it sit for 10 minutes, while you cook the syrup. Do this in the beginning when the syrup starts to boil, because it will take about 10 minutes or so, depending on how high you have your heat.

Once syrup reaches 245F, turn the heat off. Let pan sit for 2 minutes.

With the whisk attachment, start whisking gelatin mixture in the stand mixer.

Slowly, add hot syrup to the bowl, while mixer is running.

Add salt. Increase speed to high and whisk for 5 minutes, until mixture is very fluffy.

Add vanilla and mix to combine.

Using your oiled scraper or spatula, transfer mixture to the prepared pan. Smooth out the top gently.

Sprinkle some of the powder (cornstarch + powdered sugar mixture) over marshmallow.

Let marshmallow sit for a few hours to set. About 6-8 hours.

Cut marshmallows with an oiled knife. Coat marshmallows in the cornstarch + powdered sugar mixture. Shake them gently to remove excess powder.

Store in an air tight container for up to 3 weeks at room temperature.

Remove the inside of the cupcakes. Place some of the fudge mixture inside. Top with the cake part. Frost with the buttercream frosting. Drizzle the fudge sauce on top. Place the marshmallow on top. Use a blow torch to toast your marshmallows.

Store in the fridge for up to 3 days.