In a shaker add ancho mezcal, tequila, bitter liqueur, cilantro, lime juice, and agave. Add ice and shake vigorously for 30 seconds. Strain into an old fashioned glass filled with ice.
For the Ancho Infused Mezcal
Toast one dried ancho in a dry pan over high heat, turning it often until it becomes fragrant and slightly soft. Remove from heat and place in a jar. Add mezcal and cover. Allow to steep overnight, shaking jar occasionally. Remove the chili in the morning.