Coffee and Kahlúa Flan

INGREDIENTS

• 2⁄3 cup sugar
• 1/4 cup water
• 1 Tbs. corn syrup
• 1 can (14 fl. oz.) sweetened condensed milk
• 3⁄4 cup half-and-half
• 1 cup whole milk
• 2-inch piece true cinnamon bark or 1-inch piece
• cassia cinnamon bark
• 1 Tbs. Kahlúa or other coffee-flavored liqueur
• 2 tsp. instant coffee granules dissolved in 1 tsp.
• boiling water
• 5 eggs
• 3⁄4 tsp. vanilla extract