Step 1In a large bowl, mix the flour, salt and baking soda.
Step 2In the bowl of a standing mixer, or in a large bowl using a hand mixer, cream the butter and sugar, 2 to 3 minutes. Mix in the molasses until incorporated, then the egg. Mix in the grated and ground ginger, allspice, cinnamon, pepper, cloves and cardamom until combined. Wrap the dough in plastic and chill for at least two hours -- and up to one week.
Step 3Heat the oven to 375 degrees. Take half of the dough and roll out on a floured work surface to slightly less than one-fourth inch. Using cookie cutters in the desired shape, cut out the dough and place the shapes on a cookie tray lined with parchment, about 1 inch apart. Bake about 10 minutes, or until the edges of the cookies begin to color slightly. Do not over-bake. Cool cookies thoroughly on racks before frosting.
Step 1Place the egg whites and lemon juice in the bowl of a standing mixer (or in a mixing bowl, if using a hand mixer) and mix until combined. Gradually add in the sugar, mixing until well combined.
Step 2Pipe onto cookies with a piping bag (remember to cover the unused portion of the icing with plastic wrap to prevent drying out). Garnish the cookies as desired with decorations, then dry at room temperature until the icing is hardened. Store in airtight containers for up to 3 weeks at room temperature.