For the cupcakes: Preheat the oven to 350 degrees F. Use a 24 socket cupcake pan and line with paper liners. Set the pan aside.
In a medium bowl, whisk together the eggs and liqueur until blended, and set aside.
In a large bowl of an electric stand mixer on low speed, gently combine the flour, granulated sugar, hazelnut meal, baking powder, baking soda and salt until blended. Add the butter and sour cream and beat on low speed until the dry ingredients are moistened.
Increase the speed to medium and beat for 2 1/2 minutes, scraping the sides of the bowl occasionally. In three separate additions, add the egg mixture to the batter, beating for 30 seconds after each addition. Divide the batter evenly into the prepared cupcake liners and bake on the center rack until a cake tester inserted into the center of each cake comes out clean, 20 to 25 minutes. Cool the cakes in the pans for 10 minutes. Remove from the pans and cool the cakes completely on wire racks, about 30 minutes.
For the torrone filling: Mix together the butter and powdered sugar with the paddle attachment in an electric mixer. Once thoroughly combined, add the torrone paste. Continue to mix until evenly distributed.
For the chocolate hazelnut fudge: In a food processor, place the powdered sugar, cocoa and salt. Blend to remove any lumps. Add in the butter and blend until smooth. Add the corn syrup. Process just until combined, and then scrape down the sides. Pulse. Add the chocolate hazelnut spread, and then pulse until completely combined, smooth and creamy.
To assemble: Core each cupcake, and then fill with the torrone filling. Using a round tip and pastry bag, ice each cupcake with chocolate hazelnut fudge, creating a swirl on top.
This recipe was created by a contestant during a cooking competition. It has not been tested for home use.
Recipe courtesy of Julia San Bartolome, Sweet Arleen's, Westlake Village, CA