Step 1 In a small saucepan, mix cherries and syrup and heat over medium-low heat. In a small bowl, mix the cornstarch and water to form a slurry. Add the slurry to the saucepan and stir to combine. Continue to heat, stirring, until the mixture thickens slightly to a sauce-like consistency, 10 to 12 minutes.
Step 2 Stir in the cherry liqueur, remove from heat, then cover and keep warm while preparing the latkes. (May be prepared in advance and reheated.)