Baking Cookies on the Dashboard: Solar Cooking At Its Most Basic

Phoenix might be hurting for a great many things but sunshine is not one of them. To out-of-state friends I describe the heat as, "Like standing in-front of an open oven... forever."

So why not put that oven to good use? My car certainly feels like an oven when I hop into it in the afternoon and I've known people who use oven mitts to drive. After some research and a quick consultation with a local solar cooking enthusiast I came up with a quick supply list for my first foray into solar cooking:

1. Well-loved baking sheet, the darker the better.
2. Cookie dough. I went with store bought for consistency.
3. Plastic wrap.
4. Oven thermometer.
5. Oven mitts.

According to my research, optimal cooking times are from 1 PM until around 5 PM. I parked my car at 12:30 and let it sit for 30 minutes, pre-heating the oven if you will. I took this time to prepare my cookies.

I gave the baking sheet a quick squirt of non-stick spray and sliced the cookie dough into roughly half-inch rounds. I was concerned that the low cooking tempature (~190 degrees) would leave me with piles of uncooked dough so I took the extra precaution of smooshing (that's the technical term) each piece flat.

If you're playing along at home you'll want to omit both of these steps. The spray did nothing, after 90 minutes in the sun my cookies could only be dislodged with an aggressive spatula. The smooshing made the cookies thin and ridiculously crispy. I like my cookies crunchy on the outside and chewy in the middle so this was a poor choice. However, if you're looking for sun baked biscotti, smoosh away.

I covered my tray of cookies with plastic wrap and headed outside. My car was appropriately hot at this point but I decided to drive it, cookies on the dashboard, to the other end of the apartment complex. The temperature was around 105 when I drove my late model Accord into a quiet corner of my apartment complex. To help direct the solar energy streaming through my windshield I unfolded my Costco special sun shield and promptly burned myself on the already smoldering baking sheet. The sheet couldn't have been up there for more than five minutes but it was already too hot to handle painlessly. Off to a roaring start.

30 minutes in, already at 190 degrees. ​Cooking should have taken between 2-3 hours. After 30 minutes the temperature was already pushing 150. After an hour it was holding steady at just under 200. After 90 minutes my cookies were done.

Final Analysis: The cookies were actually slightly overdone. Between crushing them and leaving them unattended for thirty minute stretches, I had baked them into circular biscotti. Perhaps unsurprisingly, they tasted fine although I did detect a hint of "Bachelor Car" in their bouquet. 

Next: How to suck less at solar cooking.