Preheat oven to Preheat oven to 350°F. Line cupcake pan with cupcake liners.
Sift flour, baking soda and salt into a large bowl.
1 ⅓ cup cake flour, ¾ teaspoon baking soda, ¼ teaspoon salt
Boil water and add espresso to it, stirring until dissolved.
½ teaspoon instant espresso, ⅓ cup boiling water
Whisk cocoa powder, then buttermilk and vanilla into water/espresso mixture.
⅓ cup cocoa powder, ½ cup buttermilk, 1 teaspoon vanilla extract
Using a stand mixer, whisk sugar and butter until fluffy. About 10 minutes.
½ cup unsalted butter, 1 ¼ cup sugar
Add each egg and the yolk, one at a time, into the butter mixture, letting each one fully mix into the batter before adding the next. About 2-3 minutes of mixing in between each egg. Add in oil and mix until fully combined.
2 extra-large eggs, 1 extra-large yolk, ¼ cup vegetable oil
Fold in ½ of the flour mixture and then fold in ½ of the buttermilk mixture to the batter. Then fold in remaining flour and then remaining buttermilk mixture.
Bake for 20-25 minutes or until a toothpick inserted comes out clean.
Marshmallow Frosting
Combine egg whites, sugar, and cream of tartar in a heat proof bowl/double boiler. Set over pot of simmering water, making sure the bottom of the bowl doesn’t touch the water. Whisk until well combined and frothy. It will be slightly warm. About 7 minutes.
Add vanilla extract and food coloring if using and then transfer to a stand mixer (you can also use a hand mixer). Using the whisk attachments beat the mixture on high until stiff peaks form. About 5-10 minutes.
2 ¼ teaspoon vanilla extract*, Food Coloring
Pipe onto cooled cupcakes and stick in the fridge for about 30 minutes to help it set up.
Chocolate Shell
Melt chocolate and coconut oil. To melt, microwave ingredients for 30 seconds, and then stir. Microwave another 30 seconds, stir and repeat until everything is melted.
Dip cupcakes quickly into melted chocolate, letting excess chocolate drip off. Once all have been dipped, refrigerate for at least 10 minutes to help the chocolate set up completely.
Notes
Tips and Tricks
*I use carton egg whites for this step so I don’t have a bunch of yolks separated that need to be used up.
*You can use any extract you want to give the frosting some flavor! Besides vanilla, sometimes I’ll use almond or even orange extract!
*Refined coconut oil doesn’t have a coconut flavor, unrefined does and will work for the recipe too- but it will taste like coconut.
*I used milk chocolate chips for this recipe but you can use whatever kind you want!
For more tips on dipping and making the frosting and cupcakes see my post above!
Store leftover cupcakes in the refrigerate in an air-tight container.
Best eaten day of making but will stay tasty for 2-3 days if refrigerated.