Preheat oven to 350 degrees F.
In a food processor, puree garbanzo beans, apple puree, vanilla, and ½ cup Splenda. Blend until smooth.
In a small bowl, combine cocoa powder (or melted chocolate) with 1 cup Splenda. If using cocoa powder, combine cocoa powder with Splenda plus just enough warm water to create a thick paste.
Add cocoa mixture to garbanzo mixture in food processor. Blend until well incorporated.
Using a whisk or hand blender, whip egg whites until fluffy. Add egg whites to food processor mixture and blend for another 2 minutes.
For cookies, scoop up dough, one heaping tablespoon at a time, onto a nonstick cookie sheet or a regular sheet lightly sprayed with Pam or lined with parchment paper. For brownies, spread out mixture evenly, just as you would with regular brownie mixture, into an 8” by 8” Pyrex dish or a nonstick cooking tray.
Bake cookies or brownies at 350 degrees for 25 minutes. For the brownies, the edges should be starting to recede from the sides of the tray. Cool, then cut into 3”x 3” squares.