Preheat the oven to 325 degrees F. Lightly grease 3 (12-cup) mini-muffin pans with oil.
In a medium bowl, mix together the flour, sugar, cocoa powder, potato starch, arrowroot, baking powder, salt, baking soda, and xanthan gum. Add the applesauce, 1/2 cup oil, hot water, and vanilla to the dry ingredients and stir until the batter is smooth. Using a rubber spatula, gently fold in the chocolate chips just until they are evenly distributed throughout the batter.
Using a melon baller, scoop the batter into each prepared mini-muffin cup. Bake the brownies on the center rack for 10 minutes, rotating the tray 180 degrees after 5 minutes. Cook's Note: For a fudgier cake, bake for only 8 minutes total.
The finished brownie will have a firm edge with a soft center, and a toothpick inserted in the center will come out clean.
Let the brownies stand in the pans for 10 minutes; they are best served warm. To maintain freshness, leave the brownies in the pans until ready to serve. Cover with plastic wrap and store at room temperature for up to 3 days.
*Can be found on the web.
Reprinted from the book BABYCAKES by Erin McKenna. Copyright (c) 2009 by Erin McKenna. Photographs copyright (c) 2009 by Tara Donne. Published by Clarkson Potter, a division of Random House, Inc.