Gather the ingredients. Preheat the oven to 350°F (175°C).

In a large bowl, cream together butter and brown sugar until smooth. Stir in molasses and eggs.

Combine 1 ½ cups of the flour, baking soda, salt, allspice, cloves, cinnamon, and ginger; beat into molasses mixture. Gradually stir in remaining flour by hand to form a stiff dough.

Divide dough into 2 pieces. On a lightly floured surface, roll out dough to 1/8-inch thickness.

Cut into desired shapes using cookie cutters. Place cookies 1-inch apart onto ungreased cookie sheets.

Bake for 8 to 10 minutes in the preheated oven. Allow cookies to cool on the baking sheet for 5 minutes before removing to a wire rack to cool completely.

In a medium bowl, sift together confectioners' sugar and cream of tartar. Blend in egg whites.

Using an electric mixer on high speed, beat for about 5 minutes, or until mixture is thick and stiff. Keep covered with a moist cloth until ready to frost cookies.