
1. In a large heavy saucepan melt chocolate pieces and chocolate-hazelnut spread over low heat, stirring occasionally. Add evaporated milk and sugar, stirring until smooth. Bring to boiling over medium-high heat, stirring constantly; reduce heat. Cook, uncovered, for 8 minutes, stirring frequently. Remove from heat and stir in coffee liqueur.
2. Spoon mixture into 6 clean half-pint jars, leaving 3/4-inch headspace; cover and refrigerate. Divide hazelnuts, if using, between 6 small plastic bags. Decorate jars and plastic bags. To serve, reheat sauce, spoon sauce over ice cream; sprinkle with nuts, if desired. Makes 6 half-pint jars.