If you place a bag of holding in another bag of holding…

The “if you put a bag of holding in another bag of holding it causes a rip in the space time continuum” comment is by someone called NED!!!

Source of the Calzone Golem:
http://www.wizards.com/dnd/files/Cooking.pdf

Selected details:
Construction
A calzone golem’s body is created from a mixture of fine
ingredients, including approximately 100 pounds of
flour, 50 pounds of cheese, four gallons of tomato
sauce, and large quantities of salt, yeast, and sugar.
Mushrooms, olives, or other ingredients may be added
to the tomato sauce as desired. Season with oregano
and black pepper to taste. All ingredients must be fresh
and of the highest quality.
The golem costs 10,000 gp to create, including 500
gp for the ingredients. Assembling the body requires a
successful Profession (cook) check (DC 15), along with
2 hours of baking at approximately 450 degrees.
The creator must be 9th level and able to cast arcane
spells. Completing the ritual drains 250 XP from the
creator and requires burning hands, grease, major creation,
and stinking cloud.