I once tried making Ina Garten's roasted potato soup recipe. I ended up with a very large pot containing what looked and tasted like a mix of wallpaper paste and hagfish mucus. Another recipe that was never tried again.
I, too, would have LOVED the uber-garlic. (My favorite pizza place has one called Death by Garlic...I love it!)
I've had the thermostat on the oven go on the fritz. The smoke alarm went off before the timer did. I had a carbonized manhole cover instead of a pizza.
Also had a shocking experience with a waffle iron. Apparently there was a short or something in the wiring and when I went to pour the batter in, I got zapped and flung waffle batter all around the kitchen....twice. The large CLANG heard next was that waffle iron hitting the trash.
I was once making a red velvet cake from scratch and used AP flour instead of cake flour. Three red frisbees.
We sometimes put a teaspoon of powdered ginger into the chili when we are making it. This is for approx. 2 gallons of chili. The top came off the spice jar and somewhere around 1/4 cup went in. I tried to scoop it out but the chili was so bad the dog tried to bury it.
She wouldn't eat even a little bit, and this dog was usually a mobile garbage disposal.
Not mine, but Aunt. She was a so-so cook, good candy maker, but incredibly lousy baker. Her pie crusts were so thick and tough that when I was cutting a pie that she made during a family thanksgiving dinner, I cut through the pan too. (I was having to use the point of the knife to perforate the crust before I could slice it.) Luckily, it was just a cheap foil pie pan.
Then there was the Great Pickle Boilover. My GM's old stove had what we called a "cooker well". It was a burner recessed into the stove top with a specific pot which fit down into it. It was lovely for cooking things low and slow as the well held the heat well. We were cooking the pickling solution for a batch of zucchini pickles which had a LOT of sugar in it. It was happily simmering away when we turned away to do something else. When we looked again, the solution had boiled up and over the pot, down the side of the stove, on the floor, down in the cooker well. It took HOURS to scrub all that stuff off. The sugar in it made it really stick badly.