In a large mixing bowl, cream together butter and sugar until light and fluffy. Add the egg and molasses; beat until well mixed. Mix together the flour, baking soda, spices, and salt. Add to butter mixture and mix just until combined.
Line baking sheets with parchment paper or silicone baking mats. Drop batter by spoonfuls onto lined baking sheets.
Bake in preheated 350 degree F oven for 12 to 14 minutes. Let cool on baking sheets for 3 to 5 minutes before removing to wire racks to cool completely. Store in an airtight container.