Mix flour, ginger, cinnamon, baking soda, nutmeg, and salt in large bowl.

Beat butter and brown sugar in large bowl with electric mixer on medium speed until light and fluffy. Add molasses, egg, and vanilla; mix well. Gradually beat in flour mixture on low speed until well mixed.

Press dough into a thick, flat disk. Wrap in plastic wrap. Refrigerate 4 hours or overnight.

Preheat the oven to 350 degrees F (175 degrees C).

Roll dough on a lightly floured surface to a thickness of 1/4 inch. Cut into gingerbread men shapes with a 5-inch cookie cutter. Place gingerbread men 1 inch apart on ungreased baking sheets.

Bake in the preheated oven until edges of cookies are set and just begin to brown, 8 to 10 minutes. Cool on baking sheets for 1 to 2 minutes, then remove to wire racks to cool completely.

Decorate cooled cookies as desired. Store cookies in airtight container up to 5 days.