Combining ginger, honey, and scotch, Sam Ross's Penicillin cocktail is a natural favorite for winter sipping. But looking to make an even more warming version of the modern classic, Resa Mueller at R&D in Philadelphia switches out the scotch with tequila and mezcal and turns up the heat for this Hot Oaxacan Penicillin. "The temperature brings all of the aromatics of the smoke, agave, and rich honey to your nose," says Mueller.