In a small bowl, disolve baking soda in boiling water. Set aside.
In a large bowl, beat sugar, molasses and butter until smooth.
Blend in egg, ginger, cinnamon, salt and baking soda solution.
Blend in flour gradually.
Divide dough into quarters. Flatten each piece into a thick disk and wrap snugly with plastic wrap. Chill 2 hours or until firm enough to roll out.
Preheat oven to 350 degrees F. Dust work surface and rolling pin with flour. Remove one disk of cookie dough from the refrigerator and roll to 1/4-inch thickness. Cut with cookie cutters. Using a metal spatula, transfer cutout to an ungreased cookie sheet; space cookies about 1-inch apart.
Bake one sheet at a time for 8-10 minutes or until cookies feel firm when lightly touched.
Cool on racks. Decorate, if desired.
**NOTE: If dough becomes too firm while trying to roll, unwrap it and let it stand at room temperature for 5-10 minutes.