In bowl, cream together the butter and the brown sugar and beat in the egg yolk, the vanilla, the crystallized ginger, and the ground ginger. Into the bowl, sift together the flour, the baking powder, and the salt and combine the batter well. Drop teaspoons of the batter about 3 inches apart onto ungreased baking sheets and bake the cookies in batches in the middle of a preheated 350 degree oven for 10 to 12 minutes, or until they are just golden. Let the cookies cool on the sheets for 5 minutes, transfer them carefully with a metal spatula to racks, and let them cool completely. Makes about 50 cookies. ----