How to Make It
Whisk together first 8 ingredients and, if desired, crushed red pepper in a medium saucepan. Bring to a boil over medium heat; reduce heat to low, and simmer, whisking occasionally, 5 to 6 minutes or until slightly thickened. Cool completely before serving (about 30 minutes). Store in an airtight container in refrigerator up to 7 days.
*Store-bought coffee liqueur may be substituted.