Preheat oven to 375F.
Melt butter in a saucepan. Remove from heat, and mix in molasses. Let cool.
Sift all dry ingredients together.
Once the butter mixture has cooled enough that you won't be cooking the egg, add the egg and mix.
Combine the wet and dry mixtures and stir until thoroughly combined. Cover and refrigerate until firm- thirty minutes or so.
Fill a shallow dish with sugar.
Roll the dough into 1 inch balls, folding in a bit of candied ginger, if desired- then roll in sugar and place 2 inches apart on an un-greased baking sheet (use parchment paper if the cookie sheet is no longer shiny).
Bake on ovens middle rack for 8-14 minutes—8 minutes if you want a softer, chewy cookie, 12-14 minutes if you want a crispy cookie. In my oven 10 minutes produces a cookie happily in the middle. Rotate halfway through.
Cool on baking sheets for 5 minutes (the cookies will be too soft to remove from the pan without falling apart when first out of the oven) then transfer to a wire rack to cool fully.