Place pear, cardamom, thyme, and maple in a cocktail shaker. Muddle the ingredients together, breaking down the pear and expressing the thyme into the maple.
Add freshly juiced lemon and ice. If you wish, you can add a clear spirit of your choice (nonalcoholic like Lyres, or alcoholic for cocktail enjoyers). Shake.
Strain over crushed ice into desired glass (I shaved my ice down by putting it into a blender). Top with 2 ounces of natural grapefruit soda.
Garnish with a full pear slice and thyme sprig.