"There are few things as luxurious as having a bottle of martinis in your freezer, ready to pour at the end of a long day," writes author Maggie Hoffman in her new book Batch Cocktails. The recipe for the Invitation, created by Collin Nicholas of Portland’s Ava Gene’s and Tusk, is one of Hoffman's favorites, prized for the way the split base of two vermouths plus gin and vodka create a drink that's "silky and seamless." This recipe makes enough for 8 servings.