Tried assorted home grown solar ovens they are normally somewhat difficult (bulky) to pack and transport, the simplest was an inner tube (Do they even make these anymore?) a glass plate and a piece of foil lined fiber insulation, you need black pots.
They work OK, but are not for the impatient.
If baking, rarely anymore, my first choices are a Dutch oven or reflector oven and the campfire, I don't really consider bringing a solar oven anymore; we prefer to camp in shady forests.
Enjoy!