In a small bowl mix the ground flax seed with the warm water. Set aside to jell for at least 15 minutes, until it becomes thick and gelatinous. Put the puffed rice, dates, oil, vanilla, cinnamon, ginger, both white and cayenne peppers, salt, and the flax mixture in the work bowl of a food processor.
Process 2 to 3 minutes, until the dough sticks together in a ball.
On a piece of parchment or waxed paper, form the dough into a log about 12 inches long. Wrap the parchment around the dough and use it to round out the log. Freeze several hours or overnight, until firm enough to slice.
Preheat the oven to 350°F. Line a couple of large baking sheets with parchment paper. Slice cookies about 1/4-inch thick and arrange on baking sheets about 1/2 inch apart. (see note) If you wish, press small pieces of candied ginger into the top of each cookie
Bake 10 minutes or so, until the bottoms are light brown, darker than they were when you put them in the oven.