Combine first 7 ingredients in a 3-qt. saucepan. Bring to a boil over medium heat, stirring occasionally. Remove pan from heat; stir in baking soda. Transfer to a mixing bowl. Add butter and egg, beating at medium speed with an electric mixer until smooth. Gradually stir in flour and salt, beating just until blended.
Shape dough into a ball, and divide in half. Flatten each half into a round disk; wrap each in plastic wrap, and chill at least 1 hour or until firm.
Line several large baking sheets with parchment paper. Roll out dough, 1 section at a time, to 1/4" thickness on a floured surface. Cut into gingerbread girl shapes (we used a 5 1/2" cookie cutter from www.rochowcutters.com). Reroll trimmings to make additional cookies. Place cutouts 1/2" apart on prepared baking sheets.
Bake cutouts plain, or press raisins and cinnamon candies in each gingerbread girl for eyes, nose, mouth, and buttons, if desired.
Bake at 325° for 14 minutes or until cookies are puffed and slightly darker around edges. Cool 1 minute on baking sheets; remove to wire racks to cool completely.
Decorate cookies with Royal Icing by first outlining desired patterns for each cookie. Then fill in with additional icing, letting icing flow into outlined area. Apply candy decorations, if desired. Let icing harden at least 1 hour.
*We tested with Williams-Sonoma Winter Wonderland Decorating Kit.