Cooker we made: http://www.nmsea.org/Curriculum/4_6/pizza_box_oven/pizza_box_ovens.htm and also at this website: http://kitchenpantryscientist.com/?p=313 We did find that adding the newspaper for insulation worked much better than our previous attempts at solar cooking!
Recipe we cooked:
1 flour tortilla
creamy peanut butter (although crunchy would probably work as well)
handful of chocolate chips (we used semi sweet ones)
handful of mini marshmallows
Spread the tortilla with peanut butter then sprinkle the peanut butter with chocolate chips and marshmallows, roll up (remember to bend in the ends so the insides don't come oozing out!). Place in your solar cooker and heat for about 30 minutes!