1stick unsalted butter, melted and slightly cooled
1/2cupsemi-sweet chocolate chips
2large eggs + 1 large egg yolk, at room temperature
3/4cup+ 2 tablespoons all-purpose flour, not packed
1/2cupunsweetened cocoa powder
1/2cupfull fat sour cream
1/2cuphot coffee OR hot water
For the Nutella Buttercream:
1stick unsalted butter, very soft
1/4cupunsweetened cocoa powder
2tablespoonswhole milk or half and half
For the chocolate glaze:
1and 1/4 cups bittersweet chocolate chips
18Ferrero Rocher candies (optional, see post for more information on this product)
For the cupcakes:
Preheat the oven to 350 degrees (F). Line a 12-cup cupcake/muffin tin with cupcake liners and lightly spray the liners with non-stick spray (optional but it does help them peel right off).
Melt the oil, butter,and chocolate together in the microwave, heating in 30 second increments, and stirring between increments each time. You can also melt the oil, butter, and chocolate over very low heat on the stovetop, but I find the microwave to be much easier. Whisk mixture until completely smooth and set aside to cool.
In a medium sized bowl combine the flour, baking soda, baking powder, cocoa powder, and salt; stir together until thoroughly combined; set aside.
In a large bowl, whisk together the eggs, yolk, sugar and vanilla together; beat until smooth. Add the cooled oil/butter/chocolate mixture and whisk until smooth. Add half of the flour mixture, then half of the sour cream. Repeat the process until everything is added, and be sure to mix until JUST combined - then quickly stir in the hot coffee/water. It's important not to over mix, here! Just stir until evenly combined.
Divide the batter among the 12 liners in your prepared pan. Bake for 16-18 minutes, or until a toothpick inserted in the center comes out clean. Cool *completely before frosting.
For the Nutella buttercream:
Sift together the confectioners sugar and cocoa powder, whisking well to ensure it's bump and lump free!
Using a handheld mixer OR a stand mixer fitted with the paddle attachment, beat the butter on medium-high speed until creamy; about 2 minutes. Reduce speed to low and slowly add the sifted sugar/cocoa powder, alternating with the Nutella and milk, then add the vanilla and salt. Once all of the ingredients have been added, beat on high speed until light and creamy and combined; beat for at least 1 minute on high.
Frost cooled cupcakes and top with any decorations if desired.
Cupcakes stay fresh at room temperature in an airtight container for up to 4 days.
For the chocolate ganache:
Place chocolate chips in a wide and shallow heat proof bowl. Heat the cream in a small sauce pan over medium-heat. Bring to a boil, watching very carefully as it will happen fast. When the cream has come to a boil, remove from heat and pour over the chocolate chips. Allow the cream and chocolate to sit for minute, then whisk completely smooth. Let the ganache cool for a few minutes before you drizzle it over the cupcakes. Press a Ferrero Rocher candy on top of each cupcake and allow the ganache to set a few minutes before serving.
*If the buttercream appears too thick, add more milk or cream, one tablespoon at a time until you've reached your desired consistency; if the buttercream appears too thin, add a little more confectioners' sugar to the frosting. *If you plan to pipe your frosting "mile high" like in the photos, double the frosting recipe. Unfrosted cupcakes may be frozen for up to 2 months.