Whisk together flour, baking soda, ginger, salt, cinnamon and cloves in a medium bowl.
With an electric mixer on medium speed, beat butter and 1 cup sugar until light and fluffy, scraping down sides of bowl as necessary, 3 minutes. Reduce speed to medium-low and beat in molasses, egg and vanilla until smooth. Reduce speed to low, beat in flour mixture in 2 batches just until blended; continue to blend with a rubber spatula. Refrigerate dough, covered, for at least 1 hour, or until very firm.
Position a rack in middle of oven and preheat to 375°F. Grease 4 large baking sheets. Place remaining 1/2 cup sugar in a bowl. Shape dough into 1-inch balls, roll each in sugar, and place 2 inches apart on baking sheets. Bake cookies (2 sheets at a time) for 10 to 15 minutes, switching positions on oven racks halfway through, until tops of cookies are cracked and fall just slightly when very lightly touched. Let cookies cool on sheets on wire racks for about 2 minutes, then transfer to wire racks to cool completely.