Step 1.
- Combine Scotch, sweet vermouth, and Angostura bitters in a mixing glass filled with ice.
Step 2.
- Stir the mixture until well chilled, about 30 seconds.
Step 3.
- Strain the cocktail into a pre-chilled coupe glass.
Step 4.
- If using barrel aging, transfer the stirred cocktail into a small oak barrel and let it age for 1-2 weeks.
Step 5.
- After aging, pour into a fresh coupe glass.
Step 6.
- Garnish with a maraschino cherry.