Chocolate Hazelnut Torte Recipe

In a small bowl, cream butter and brown sugar until light and fluffy. Beat in egg and vanilla. Combine the flour, cocoa, baking soda and salt; gradually add to creamed mixture alternately with sour cream and coffee. Beat just until combined. Pour into two greased and floured 6-in. round baking pans. Bake at 350 ° for 25-30 minutes or until a knife inserted near the center comes out clean. Cool for 10 minutes before removing from pans to wire racks to cool completely. For frosting, in a small saucepan, melt chocolate with cream and sugar over low heat; stir until smooth. Remove from the heat; whisk in Nutella. Transfer to a small bowl; cover and refrigerate until frosting reaches spreading consistency, stirring occasionally. Spread frosting between layers and over top and sides of cake. Garnish with chocolate curls and hazelnuts if desired.