Heat medium saucepan on medium-high heat 2 minutes. Add chilies; toast 30 seconds per side or until they begin to blister and change color slightly. Let saucepan cool slightly. Add 2 cups water to cover chilies. Bring to boil. Reduce heat to low; simmer 30 minutes until chilies soften.
Remove chilies with kitchen tongs to blender container. Add 1/2 cup chile soaking liquid; cover. Blend on high speed until smooth. Discard remaining soaking liquid in saucepan.
Strain chile puree through large mesh strainer into saucepan. Stir in cream and corn syrup. Bring just to boil on medium heat, stirring occasionally. Remove from heat. Add remaining ingredients; stir until chocolate is melted and mixture is smooth. Garnish with toasted sesame seed.