Chocolate cupcakes with hazelnut filling

Ingredients:

Cupcakes

• 1.5 cups premium flour
• 1 teaspoon baking powder
• 2 teaspoons of baking soda
• 0.5 tsp salt
• 1 cup nut liqueur
• 1 cup cocoa powder
• 1 cup of butter at room temperature
• 1 cup dark brown sugar
• 1 cup granulated sugar
• 3 eggs
• 1 cup of sour milk or kefir
• 1 tbsp vanilla extract

Hazelnut filling

• 1.5 cups whole hazelnuts
• 1/3 cup chocolate-hazelnut spread (preferably Nutella)
• 3-4 tablespoons of nut liqueur
• 0.5 tbsp. flour for dredging

Chocolate ganache

• 0.5 cups heavy cream
• 3/4 tbsp. semi-sweet chocolate granules
• 0.5 tsp espresso powder, optional
• 1 teaspoon vegetable oil, optional

Preparation:

1. Preheat oven to 175°C. Line 24 paper cupcake liners with the filling.
2. Cupcakes:
   
   In a medium bowl, sift together the flour, baking powder, baking soda, and salt. Mix the nut liqueur with the cocoa powder until smooth.
3. In the bowl of a stand mixer fitted with the paddle attachment, beat the butter and sugar on medium-high speed until light and fluffy, 2-3 minutes. Add the eggs, one at a time, until fully incorporated.
4. Add the sour milk and vanilla extract and mix until fully incorporated. Reduce mixer speed and add the flour mixture, alternating it with the cocoa-liqueur mixture, beginning and ending with the flour. Knead into a smooth dough. Set aside while you prepare the filling.
5. Filling:
   
   In a food processor, puree the hazelnuts until they resemble very fine sand. Add the chocolate spread and process until the mixture begins to clump together. Add the hazelnut liqueur, 1 tablespoon at a time, or until the mixture clumps easily in your hand.
6. Using your hands, form the paste into balls the size of a very large cherry. Lightly coat the balls in flour to absorb excess liquid.
7. Fill the muffin tins about a quarter full with batter. Place one scoop of filling in each tin, then top the filling with the remaining batter until each cup is about three-quarters full.
8. Bake until a toothpick inserted into the center of the cupcake comes out clean, 20 minutes. Let cool completely.
9. Chocolate ganache:
   
   Dip the top of each cupcake into the chocolate ganache to coat evenly and let set.
10. Microwave the heavy cream in a bowl for 1-2 minutes. It should be very hot to the touch. If the ganache starts to set prematurely or the cream isn't hot enough, place the bowl over a pan of simmering water.
11. While the cream is heating, place the chocolate and espresso powder in a medium heatproof bowl. Once the cream is hot, pour it over the chocolate and stir until the chocolate is completely melted and the ganache thickens. Add vegetable oil for extra shine.