Flattening the salty-sweet ginger dough with the bottom of a sturdy glass ensures cookies of uniform size and thickness. The cookies can be made in advance and sandwiched with sorbet shortly before serving.
Preheat oven to 325 degrees. Whisk flour, ground ginger, salt, baking soda, cinnamon, and cloves in a bowl.
With an electric mixer on medium speed, beat butter and sugar until pale and fluffy, 2 to 3 minutes. Mix in egg, then add molasses and candied ginger. Reduce speed. Gradually mix in flour mixture. Wrap dough in plastic, and refrigerate until slightly firm, 15 minutes.
Using a 1 1/2-inch ice cream scoop, drop balls of dough onto parchment-lined baking sheets. Roll each one in sugar, and return to sheets, spacing 2 inches apart. Using the bottom of a glass dipped in sugar, press dough to flatten into 3-inch rounds. Bake until edges are golden brown, 8 to 10 minutes. Let cool completely. Cookies can be stored in airtight containers up to 2 days.
Sandwich one scoop of sorbet with 2 cookies. Repeat, alternating sorbet flavors. Serve immediately, or freeze in airtight containers up to 3 hours.