The Buttercup is a warming, malty, just-sweet-enough cocktail originally from the Bols company, and later refined and perfected by master mixologist Simon Difford.
Difford advises that if you choose to use a lemon twist for garnish, you shouldn’t express it over the drink; the lemon oil is too strong and will overpower the butterscotch. We like the scent of the twist, but we do agree with Diffords’ postulate.
Oude genever is better than jonge here, but either one is acceptable.