Preheat the oven to 350 degrees Fahrenheit.
Let margarine soften, and then mix with applesauce, sugar and vanilla. Beat in the cornstarch mixture.
Mix in cocoa, then baking soda and baking powder, then salt, then flour.
Add the wheat bran little by little (while mixing) until desired consistency (a little less stiff than your regular cookie dough. I use about 1/2-3/4 cup.).
Plop spoonfuls of the batter onto a lightly greased cookie sheet. Bake 8-10 minutes, until the tops are fairly solid.
These make soft, somewhat low-fat cookies. A friend analyzing these cookies observed that they are more like a cross between brownies and bran muffins. But a good cross, I assure you :)
* when I don't have cocoa on hand I use 2 oz dark chocolate (70%), melted. It works great.