Slice the tops off dwarf pineapples. Scoop the flesh out of the pineapples, and reserve. Freeze hollowed pineapple "cups" at least 4 hours or until ready to use. Blend reserved pineapple flesh until smooth. Strain through a fine mesh strainer to yield 2 cups pineapple juice. Combine strained pineapple juice, gin or vodka, lime juice, and agave or simple syrup in a pitcher; stir. Divide mixture among frozen pineapple cups. Garnish each with a straw and a swizzle.