In a mixing glass, add 2 oz barrel-aged bourbon, 0.75 oz sweet vermouth, 0.5 oz amaro, 0.25 oz simple syrup, 3 dashes orange bitters and 2 dashes lemon bitters.

Stir

Fill the mixing glass with large ice and stir gently but thoroughly for 20–30 seconds (about 20–30 full spoon turns) until well-chilled and lightly diluted.

Prepare glass

Discard ice or water from the chilled rocks glass. Place a single large ice cube into the glass.

Strain

Using a strainer, pour the stirred cocktail over the large ice cube in the rocks glass.

Express garnish

Take an orange peel and a lemon peel. Hold the orange peel over the drink and give it a firm twist skin-side down to express oils over the surface, then rub the peel rim on the glass and drop it onto the ice. If using the lemon peel, lightly express over the drink and discard or tuck in as desired.

Final aromatic touch

Optionally add 1–2 extra dashes of orange bitters on top for an aromatic lift. Serve immediately.

Notes

Adjust sweetness by increasing or decreasing simple syrup by 0.125–0.25 oz. Swap the amaro for a different style to change bitterness/herbal profile. Barrel-aged bourbons with deeper caramel and oak notes work best to evoke the 'dusk' character.