Muffin protector

Container with friction-fit push-on lid to prevent muffins being damaged when travelling.
Dimensioned and shaped for blueberry muffins from Willy's supermarket. 70-74 mm diameter, 60mm height.
The top of the muffin sticks out of the base into the lid. This is deliberate so that the container takes less space when empty.
The inside can be varnished if you want it to be easier to clean.
You may need to adjust settings to get a good friction fit.
You could also sand or varnish to make small adjustments to the fit.