I’d heard you could fry eggs on a hot sidewalk. My frugal mother would never let me have one to sacrifice. I tried it as an adult. It didn’t work. People had to step around it. It drew flies. I eventually hosed it away. That’s why I had my doubts when my partner, Lisa, suggested we try making a solar cooker. Even though the central plains had been slowly steaming under the lid of high pressure for the better part of July, the idea didn’t appeal. Fool me once, shame on you. Fool me twice…

Instead of grousing about the apocalypse, why not make it fun, Lisa said. Not only would the cooker require no energy or emit any pollution, it would also keep cooking heat out of the house. She downloaded free plans here for something called the All Season Solar Cooker (ASSC), a do-it-yourself project that costs under $40 to build. A trip to Cottin’s Hardware later, and we had all but one item, the corrugated plastic for the body. We finally located it at Lawrence’s Sign D’Sign. Lisa’s patience and rigging skills served her well. Within a day, we had a shiny adjustable cross between something you’d put out for the trash and a satellite dish to position in the southwest corner of the backyard, which gets full afternoon sun.

All we needed was a recipe that wouldn’t kill us if our experiment failed. We decided my mother’s Depression-era chocolate cake that requires no eggs or milk would be our safest bet.

The cooker’s designer, Jim La Joie, suggests you use black cookware. All we could find was a cast-iron skillet that we didn’t want to cut the handle off of so it would fit inside the recommended oven bag. The closest we could come was a blue glass pie plate. We poured in the batter and covered the plate with a glass bowl. We tucked the whole thing in the required oven bag, put on sunglasses (so we didn’t blind ourselves), set it on the cooker, and waited. Three hours later, we had a cake still slightly doughy only in the center. We finished it off in the microwave.

The ASSC has had a larger environmental and cultural impact as well. It has been a real boon for refugees in Goma, the Republic of Congo. With help from microloans, they build the ovens from locally available materials, then sell them to generate vital income. Similarly, refugees of violence in Darfur now living in Khartoum, Sudan, use the ASSC themselves. Though Khartoum gets more sun than most cities around the world, 25 percent of an average income must be spent on charcoal for cooking.

Since its maiden voyage, we have used the ASSC to make local plum “crisp” that, though piping hot and tasty, should have been called plum “soggy.” If we find the proper cookware, there just might be no stopping us.

Though he doesn’t charge for the plans, La Joie would like you to send photos of your cooker on-location and a report of how it worked.