Heat oven to 350°F; line sheets with parchment.
Whisk flour, ginger, cinnamon, baking soda, and salt in medium bowl; set aside.
Beat butter and brown sugar in large bowl 2-3 minutes until fluffy. Beat in molasses, egg, and vanilla thoroughly.
Gradually mix in dry ingredients to form dough; do not overmix.
Roll into ¾-inch balls; place 1 inch apart on sheets.
Bake 8-10 minutes until edges just set; centers will look slightly underdone.
Cool on sheet 5 minutes; transfer to racks to cool completely. Optionally decorate with white icing.