- Combine flour, cream of tartar, baking soda and nutmeg in a bowl. Set aside.
- Beat together in a large bowl the melted shortening and the brown sugar. Beat in the eggs, then the vanilla extract. Gradually blend in the dry ingredients.
- Shape dough into a log measuring 1½ inches in diameter. Wrap log in waxed paper or foil and chill for 4 hours or overnight.
- Preheat oven to 375°F (180°C). Lightly grease 2 baking sheets.
- Slice log into slices ¼ inch thick. Place slices 1 inch apart on the baking sheets.
- Bake for 8–10 minutes until lightly colored. Cool on wire racks.