Preheat your oven to 350°F/175°C and place 12 cupcake liners in your cupcake.
In a large bowl, whisk together the flour, sugar, light brown sugar, cocoa powder, baking powder, baking soda and salt. Set aside.
1 cup + 2 tablespoons all purpose flour, ½ cup granulated sugar, ½ cup light brown sugar, ½ cup natural cocoa powder, ½ teaspoon baking powder, 1 teaspoon baking soda, ½ teaspoon kosher salt
In a large jug, whisk the eggs, oil, sour cream, and vanilla until smooth
2 large eggs, ⅓ cup vegetable oil, 1 teaspoon vanilla extract, ½ cup sour cream
Pour the wet mixture into the flour, stirring until it is just about smooth - we don't want to over mix the batter! Then pour in the hot water and mix until smooth.
½ cup hot water
Fill the cupcake liners so they're ¾ full 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.
Peanut Butter Frosting
In a stand mixer with the whisk attachment, or a large bowl with a handheld mixer, whisk the heavy cream, salt, sugar and vanilla on medium-low for 2 minutes. The sugar needs to have completely dissolved.
¾ cup granulated sugar, 3 teaspoons vanilla extract, 1 cup heavy cream, ½ teaspoon kosher salt
Increase the speed to high and whisk for 2 minutes, until it looks very thick like Greek yogurt.
Add the cream cheese and the peanut butter. Turn the speed to high, and whip for 3 minutes until smooth.
1½ cups cream cheese, 1 cup smooth peanut butter
Frost your cupcakes and enjoy!
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. I have provided a conversion to US cups but please note that I haven't tested the recipe with this method. 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. Please note, I'm using Diamond Crystal kosher salt and not Morton salt which is too salty! Peanut Butter: I recommend using smooth creamy peanut butter, and not the type of natural peanut butter that has oil on top. Cocoa Powder: I'm using natural unsweetened cocoa powder (not sure what you have? Check the ingredients. If it says 'acidity regulator' or mentions 'alkali', then it's dutch processed). Storage: You can store the cupcakes in the fridge for 3-4 days. I recommend letting it come to room temperature before enjoying!