If you’re making Steven Raichlen’s Cola-Can Chicken, a riff on the classic Beer-Can Chicken, you’ll have half a can of soda leftover. Turns out you can can use that extra cola to spice up your barbecue sauce. The resulting sauce also goes well with pork, brisket, ribs and salmon, says Raichlen, in his newly revised cookbook, “Beer-Can Chicken,” just out from Workman Publishing. Cola Barbecue Sauce Makes about 1½ cups INGREDIENTS 1 tablespoon butter 1/4 cup minced onion 1 tablespoon peeled minced fresh ginger 1 clove garlic, minced 3/4 cup cola (reserved from Cola-Can Chicken) 3/4 cup ketchup 1/2 teaspoon grated lemon zest 2 tablespoons fresh lemon juice 2 tablespoons Worcestershire sauce 2 tablespoons A.1.