Place the butter and sugar in a large mixing bowl, and cream together until pale and fluffy (about 3 minutes).
Add the eggs and molasses, mixing until combined.
Add the flour, crystallized ginger, ground ginger, baking soda, cinnamon, cloves, salt, and cayenne (if using), and mix until combined.
Scoop dough into 1-inch balls, and roll to coat in white sparkling sugar.
Place 1 1/2-inches apart on prepared baking sheets, and bake for 8-9 minutes, or until the edges are set but the centers are still quite soft (do not overbake).