Not a cooking disaster, although I've had my fair share of those...but a cute story nonetheless...
My BFF (we were about 6 at the time) wanted to really, really, really help her Mom one day, so she decided she was going to wash and wax the linoleum kitchen floor. The washing went well (only used water because she couldn't read the bottles to see which was soap), the waxing...not so well. Even though she didn't read, she remembered what the wax bottle looked like, so she took it out and proceeded to wax the floor. Boy was her mom surprised when her shoes stuck to the floor...yup, the floor was waxed with pancake syrup! [51 years ago and I remember this as if it were yesterday].
