Step 2: Cover the inside/bottom of the flap in tin foil, gluing it in place with the shiny side facing out. Make sure to do so gently, keeping the tin foil as smooth as possible. Cover the rest of the inside of the box with foil as well.

Step 3: Lay your clear plastic across the top of the opening, making sure the flap is still open. Tape down the plastic to seal the box tightly.

OPTIONAL: If you want, you can add two layers of plastic wrap to trap even more heat inside your solar oven.

Step 4: Prop the box’s flap to stay open using a stick, pole, ruler, or anything else you can find. You may have to tape it to ensure it stays open.

When you are done, place the box in the sun and allow it to get hot for about 30 minutes.

Step 5: Once the box is preheated, open one side of the plastic wrap and place the pie tin inside the box.

Set down 2 graham crackers, with a square of chocolate and a marshmallow on top of each, inside the tin. For now, leave the top graham cracker off of the s’more.

Step 6: Seal the plastic wrap tightly again, making sure there are no holes. Point your box towards the sun, angling the flap so that it will reflect the light and heat into the box.

TIP: By securing the plastic wrap, you will trap more heat, and your s’mores will roast faster!

Step 7: All that is left is to wait! Your s’mores should take anywhere between 30-60 minutes to roast. Once roasted, the marshmallows will be soft, and slightly goopy, and the chocolate will be melted.

Looking for more ways to harness the power of the sun? Check out the We’ve Got the Power Mission on the Earth Rangers app to learn all about solar power (along with other types of green energy).