Place the sugar (or 1/2 tsp simple syrup) in the bottom of an old fashioned glass. If using granulated sugar, add the Angostura bitters directly onto the sugar (3 dashes) and a teaspoon of club soda (optional) to help dissolve; muddle or press with the back of a spoon until the sugar is mostly dissolved. If using simple syrup, stir the bitters into the syrup in the glass.

Add bourbon and ice

Pour 2 oz bourbon over the sugar-bitters mixture. Add one large ice cube (or fill the glass with several ice cubes).

Stir

Using a bar spoon, stir gently for about 20–30 seconds (or 10–15 full spins) to chill, dilute slightly, and integrate the flavors.

Garnish

Express the oils from one large strip of orange peel over the surface of the cocktail by holding it over the glass and giving it a quick pinch. Run the peel around the rim, then drop it into the glass as garnish.

Serve immediately. Optionally serve with a small additional splash of club soda on the side if desired.

Tools

Use the muddler or the back of a spoon to dissolve sugar if using granulated sugar. Use a peeler or sharp knife to cut a 1.5–2 inch strip of orange peel, avoiding too much pith. Use a bar spoon to stir the drink smoothly.