I'm not gonna lie, I stole this fantastic recipe from myrecipes.com. It just looked too wonderful to not try!
What you need:
1 cup unsweetened cocoa powder
1 cup granulated sugar
1/2 cup espresso powder
1 cup powdered milk
1/2 teaspoon salt
1/2 cup chopped bittersweet chocolate or miniature chocolate chips
I simply halved each part of the recipe to add more layers. I thought it looked kinda fun to have a few crazy layers, and it made it easier not having to worry about perfection.