Preheat oven to 350 degrees F. Grease and lightly flour a 10-inch fluted tube pan. In a bowl whisk together coffee, sugar, oil, honey, vinegar, and vanilla. Add eggs; whisk until combined. In another bowl combine flour, cocoa powder, baking powder, soda, salt, and nutmeg. Whisk in coffee mixture until combined. Add the 1 cup hazelnuts; stir to combine. Pour batter into prepared pan.
Bake in preheated oven about 1 hour or until a wooden pick inserted near center comes out clean. Cool in pan on wire rack for 20 minutes. Remove from pan to a serving platter. Brush with some of the Coffee-Hazelnut Syrup. Cool for 30 minutes. Brush again with syrup. Sprinkle with the 1/4 cup hazelnuts. Serve cake warm with remaining syrup. Makes 12 servings.
In a saucepan combine brown sugar, powdered sugar, butter, and strong brewed coffee. Bring to boiling, stirring to dissolve sugar. Reduce heat. Boil gently, uncovered, for 25 to 30 minutes or until mixture thickens slightly and is reduced to about 1-1/3 cups. Remove from heat. Stir in hazelnut-flavored liqueur. Makes about 1-1/2 cups.