How to Build a DIY Solar Oven for Delicious Sun-Baked S'mores

Eco-friendly, STEAM fun for kids on a hot summer day

By Courtney Jennings, publisher of Macaroni KID Acadia-St Landry, La. June 24, 2024

With the blazing hot days of summer upon us, the thought of building a campfire is out of the question. But my family found a cool and creative way to utilize these hot summer days for a tasty camp-style treat!

Last year my daughter learned how to create a 'solar oven' for making hot dogs and s'mores while attending Girl Scout camp. We thought this STEAM project would be fun to try at home to take advantage of the scorching hot temps. Our solar oven worked well, and the kids loved this project, so we wanted to share how we did it so you can try it too!

What you need:

  • A sturdy cardboard box with a lid
  • Aluminum foil
  • Black construction paper
  • Clear plastic wrap
  • Tape or glue (optional)
  • Scissors
  • Pencil or marker
  • Ruler
  • A stick or skewer to hold up the lid
  • S'mores ingredients (graham crackers, chocolate, marshmallows)

Mom tip: We used mini marshmallows and chocolate discs because I felt like they'd melt quicker and easier than the larger marshmallows and chocolate squares.


  1. With your clean cardboard box flat, use a marker and a ruler to outline a square on the top. Use scissors or a box cutter to cut out 3 sides of the square to create a 'window,' leaving about a half inch of an edge. 
  2. Now you want to create a reflective surface. Cut a piece of aluminum foil slightly larger than the inside of the box lid. Wrap the inner part of the cardboard lid with tinfoil and line the inside of your box completely with the foil, making sure it's smooth and shiny. Secure the edges with tape as needed. 
  3. Glue or tape a sheet of black construction paper inside the bottom of the box. This will be your cooking platform. You may need to cut one of the sides of the construction paper to fit inside the bottom, depending on the size of the box you chose. The black sheet will absorb the sun's rays and convert it into heat.
  4. Assemble your s'mores! Place graham cracker squares on the black sheet of paper in your oven, add the pieces of chocolate bar, and finally, the marshmallows! (Mom tip: We found it best to leave off the top graham cracker so the marshmallows were directly in the sun.)
  5. Place plastic wrap on top to cover the window opening of the box and tape it in place. This will hold in the heat and also helps keep off the flies and other pesky insects that might be attracted to your sweet treats while they're cooking. 
  6. Place your skewer or stick through the plastic wrap in the left bottom corner of the box and hot glue or tape the top of the skewer to the top left corner of the foil-wrapped cardboard 'lid' to prop it in place. 
  7. Carefully place your DIY solar oven in the sun, making sure it is angled directly towards the sunlight for about an hour, or until the chocolate and marshmallows melt. 
  8. Once the s'mores are  'cooked,' you can remove the plastic wrap, top it with another graham cracker square to finish it off, and then enjoy your sun-cooked treat!

Always have adult supervision when using sharp objects like scissors and box cutters, and be cautious when handling the solar oven, as it may get hot. 

Have fun and enjoy your eco-friendly cooking adventure!

Courtney Jennings is the publisher of Macaroni KID Acadia-St Landry, La.