This Bobby Burns recipe is very similar to the Rob Roy, which is another famous Scotch cocktail. The only difference is that this recipe uses equal parts of scotch and sweet vermouth, whereas Rob Roy uses a two-to-one proportion.
This recipe also uses half an ounce of Benedictine instead of dashes of bitters for the Rob Roy. However, the Bobby Burns has a unique taste because it is made with blended scotch whisky.
You can use any sweet vermouth you like, but choosing the dryer, more botanical types for the best combination with the scotch whiskey is usually recommended.