1In large bowl, mix 1 1/2 cups granulated sugar, the shortening, molasses and eggs until well blended. In small bowl, dissolve baking soda in water; stir into molasses mixture. Stir in remaining cookie ingredients until well blended. Cover and refrigerate at least 2 hours.
2Heat oven to 375°F. Lightly grease cookie sheet. On floured surface, roll dough 1/4 inch thick. Cut with floured 2 3/4-inch round cutter (or cut with clean food can with both ends removed, such as rectangular-shaped pork luncheon meat can). Place about 2 inches apart on cookie sheet.
3Bake 8 to 10 minutes or until light brown. Remove from cookie sheet to cooling rack. Cool completely, about 30 minutes.
4In 2-quart saucepan, sprinkle gelatin on cold water to soften; stir in 1 cup granulated sugar. Heat to a rolling boil; reduce heat. Simmer uncovered 10 minutes. In large bowl, place powdered sugar and hot gelatin mixture. Beat with electric mixer on medium speed about 2 minutes or until foamy. Add vanilla, baking powder and salt; beat on high speed 12 to 15 minutes or until soft peaks form. Frost bottoms of cookies with frosting. Let stand until frosting is dry, 2 to 3 hours, before storing.