1. In a large bowl, whisk together first 8 ingredients; set aside.

2. Place crystallized ginger in a food processor with a metal blade. Pulse to coarsely chop. Add brown sugar and zest, and process until ginger is finely chopped and incorporated into the sugar.

3. Combine butter and sugar-ginger mixture in a bowl; cream together until light and fluffy. Add molasses; beat to combine. Add egg; beat to combine. Add dry ingredients, and mix to combine. Divide dough into 2 equal portions and drop onto large sheets of plastic wrap. Flatten into disks about 1-in. thick and wrap tightly. Refrigerate at least 2 hrs.

4. Preheat oven to 375°F. Line baking sheets with parchment paper or butter the sheets. Roll out dough on a well-floured surface, 1 portion at a time (keep remaining dough refrigerated), to 1/8- to 1/4-in. thickness. Cut into shapes. Place 1 in. apart on baking sheets.

5. Bake 6 to 8 min. Cool cookies on pan for about 8 min. Transfer directly onto a wire rack to cool completely. Re-roll dough scraps and cut out more cookies.

6. To make icing, combine butter, sugar, salt and vanilla in a mixer bowl. Beat at low speed, gradually adding juice until the desired consistency. Decorate completely cooled cookies as desired using small bits of candied ginger for eyes and buttons.