Begin by preheating oven to 350°F (175°C), and place 12 cupcake liners in cupcake pan.

Add 3/4 cup of (VERY) hot water into a large bowl.

Carefully pour in 1/3 cup melted chocolate chips, 1 tsp instant espresso powder, and 1/3 cup sifted cocoa powder.

Whisk together until the ingredients have combined.

Sift the dry ingredients into the wet ingredients (3/4 cup gluten free flour, 3/4 cup granulated sugar, 1/2 tsp salt and 1/2 tsp baking soda) into chocolate espresso mixture, and stir until combined.

Scrape the sides and bottom of the bowl as needed with a spatula.

Add 2 large eggs, 1/3 cup vegetable oil, 1 tsp vinegar, and 1 tsp vanilla, and mix until the batter is smooth.

Mix the batter for an additional 2 minutes, to help give the batter structure. You don't have to worry about overmixing, because there's no gluten in this batter!

Cover and let the batter sit for about 30 minutes, to give the gluten free flour tiem to absorb more of the liquid in the batter.

Fill cupcake liners 3/4 full, and bake for about 18-19 minutes, or until a toothpick comes out clean.

Allow the cupcakes to cool for 5 minutes before moving them to a cooling rack to finish cooling.

Beat the butter on a medium speed for 30 seconds with a paddle attachment, until smooth. 

Mix in the vanilla extract and salt on a low speed.

Slowly add in the powdered sugar in two installments. Alternate with the heavy cream.

Mix in the cooled, melted chocolate.

Beat on low until the ingredients are fully incorporated, and the desired consistency is reached.

If the frosting is too thick, add an extra Tbsp of heavy cream. If it's too thin, add in another 1/2 cup of powdered sugar.

Stir by hand with a rubber spatula to get the frosting SUPER smooth.

Place in a piping bag fitted with an Ateco 869 tip, and pipe a swirl on top of each cupcake.