Preheat your oven to 350°F/175°C and place 12 cupcake liners in your muffin tray. This recipe makes about 14 cupcakes, so you will need to make these in two batches.
In a large bowl, whisk together the flour, cocoa powder, baking powder, baking soda and salt. Set aside.
¾ cup all purpose flour, ½ cup cocoa powder, ¾ teaspoon baking powder, ½ teaspoon baking soda, ½ teaspoon kosher salt
In a mug or cup, mix together the espresso powder and 2 tablespoons of hot water to make coffee. If not using espresso you can skip this step!
1 teaspoon espresso powder, 2 tablespoon hot water
In a large jug, whisk the eggs, coffee, greek yogurt, oil, vanilla extract, vinegar and two sugars until smooth
2 large eggs, ½ cup sugar, ¼ cup vegetable oil, 1 teaspoon vanilla extract, ½ cup greek yogurt, 2 teaspoon white vinegar, ½ cup light brown sugar
Pour the wet mixture into the flour, stirring until it is just about smooth - we don't want to over mix the batter!
Fill the cupcake liners ¾ of the way and bake for 18-20 minutes. A toothpick inserted should come out clean.
Allow the cupcakes to cool for 15 minutes in the tray, then take them out and place on a cooling rack. Bake the last two cupcakes.
Make Frosting
In a stand mixer fitted with the paddle attachment, beat the butter and confectioners' sugar together on low speed until well combined.
Increase the speed to medium-high and beat for 2 minutes until it becomes very thick.
Stop the mixer and add the salt, food gel, and mint extract. Beat on medium-high speed for another 2 minutes.
kosher salt, mint extract
Turn the mixer to your lowest speed and pour in the heavy cream. Beat until it becomes very creamy and spreadable.
¼ cup heavy cream
Frost your cupcakes! I used a Wilton 1M piping tip to frost my cupcakes.
Notes
My recipes have been developed and tested in metric grams. I highly recommend using a weighing scale and measuring out your ingredients the metric way. Just click on 'METRIC' above the ingredients list. I make sure that all of my ingredients are at room temperature before I start the recipe, so pull out all of the ingredients (including the Greek yogurt!) before you start baking. Butter: I use European style butter in my recipes. This will make your finished bake much creamier and richer.Salt: If you don't have kosher salt, halve the amount of salt called for in the recipe. 1 teaspoon kosher salt = ½ teaspoon fine salt.Greek Yogurt: If you don't have Greek yogurt you can use sour cream. Cocoa Powder: I'm using dutch processed cocoa powder (not sure what you have? Check the ingredients. If it says 'acidity regulator' or mentions 'alkali', then it's dutch processed). If you want to use natural cocoa powder, then don't add the vinegar to the batter. Food Gel: I'm using Americolor food gel in the shade 'Mint Green'Mint Extract: make sure you're using mint extract and not peppermint extract.Mint Chocolate Cupcakes: you can add ½ teaspoon of mint extract to the cupcake batter instead of vanilla extract to make these extra minty. Espresso Powder: this won't make it taste like coffee, it just deepens the chocolate flavor. Feel free to leave it out. Storage: Store the cupcakes in the fridge for up to 3 days. Let them sit at room temperature for 30 minutes before eating.