Start by making your white chocolate ganache filling as it needs time to set. Place the chopped white chocolate in a heat proof bowl.
12 oz white chocolate
Pour the heavy cream into a small or medium saucepan on the stove over medium-low heat until it begins to simmer.
½ cup heavy cream
Pour over the white chocolate and let sit for a few minutes.
Using a rubber spatula, stir until smooth. If you still have pieces of white chocolate, place in the microwave in 10-second increments until smooth. Overheating it will cause the ganache to go grainy so be careful!
Place the bowl in the fridge for 1-2 hours until set, or let it set at room temperature. While it sets, make the cupcakes.
Preheat the oven to 350°Fahrenheit/175°Celsius. Place 14 cupcake liners in 2 cupcake pans. This recipe makes 12-14 cupcakes.
In a bowl, whisk together the flour, salt and baking powder.
1 ½ cups cake flour, 2 teaspoons baking powder, ½ teaspoon kosher salt
In a stand mixer fitted with the paddle attachment, or in a large bowl with a handheld mixer, combine the butter, oil and sugar for 2-3 minutes on medium speed until light and fluffy.
¼ cup unsalted butter, ¾ cup granulated sugar, ¼ cup neutral oil
Add the eggs and vanilla extract and mix to combine.
2 large eggs, 1 teaspoon vanilla extract
Mix in the sour cream.
¼ cup sour cream
Add in the dry ingredients and mix until just combine, then slowly pour in the milk.
½ cup whole milk
Using a spoon or a medium cookie scoop, scoop out the cupcake batter into the liners. You want them to be about ¾ full.
Bake for 18-22 minutes. Let the cupcakes cool in the pan for 10 minutes before removing and letting them cool completely on a wire cooling rack.
In a stand mixer fitted with the paddle attachment, or in a large bowl with a hand held mixer, combine the room temperature butter with the confectioners' sugar on low speed. Once combined, increase the speed to medium-high and beat until light and fluffy
Increase the speed to medium-high and beat for 2-3 minutes, until light and fluffy.
If the frosting isn't as creamy as you would like, add in the heavy cream and beat on medium speed until spreadable. You might not need all of it!
¼ cup heavy cream
At this point, your ganache should be set. Use a handheld mixer to whip the ganache until light and fluffy, this should take 1-2 minutes.
Use the base of a large piping tip to core the cupcakes. Press gently down into the top of the cupcake to create a hole. You don't want to go all the way down!
Spoon or pipe the whipped white chocolate ganache into the cupcakes.
Frost the cupcakes with a Wilton 1M piping tip and enjoy!
Notes
My recipes have been developed and tested in cups and metric grams. I highly recommend using a weighing scale and measuring out your ingredients the metric way.I make sure that all of my ingredients are at room temperature before I start the recipe, so pull out all of the ingredients before you start baking.Butter: I use European style butter in my recipes. This will make your frosting much creamier and richer.Cake Flour: you can swap it out for all-purpose flour but your cupcakes might not be as soft. If you're in the UK, use plain flour. Cake flour in the US is a low protein flour, it isn't flour like self-rising flour! 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 am using Diamond Crystal kosher salt and not Morton Salt, which is far too salty for this recipe. White Chocolate: Make sure you're using a high-quality white chocolate bar and chop it up finely. Lower quality white chocolate will seize up or go grainy with the heavy cream.Dark Chocolate: You can swap out the white chocolate for dark chocolate ganache. Sour Cream: You can swap out sour cream for full-fat Greek yogurt or creme fraiche. Storage: Keep in an airtight container in the fridge for up to 5 days. Let it come to room temperature before eating.