These seem like a…bad idea? Silicone is an insulator, heat is not going to transfer through these at nearly the same rate as it would through a glass or metal vessel. Recipes would definitely require alteration, likely lower temps and much longer cook times, to avoid ending up overcooked on top and undercooked on the bottom. Bread or cookies or brownies or whatever I would expect to just not work at all in these.
@Aspirant_Fool These could work for some recipes that only require a surrounding heat source, but I do a lot of oven-cooking that requires that metal contact (for caramelization or browning/charing) that these wouldn’t work with …
I’ve got Jiffy cornbread mix baking in two of the smaller square ones right now. So far, it appears that putting them on a stainless cookie sheet makes the heat-conduction issue worse, and is likely to increase the baking time rather a lot. Shortly, we will know the results.
No surprise, the one toward the back of the oven is almost perfect at 23 minutes, and the one closer to the door is about a minute or two shy. Swapping the sheet around for two more minutes, and I’ll pull them out then.
After the fact, I noticed that the stale date on the mix was 50 weeks ago. That explains the failure to rise. Otherwise, the pans appear to slow the heat transmission somewhat, and require some time adjustments, but the results were acceptable.
OBTW, I greased them with lard; silicone may be inherently nonstick, but when the recipe recommends greasing the pan, they probably want that done to promote the desired surface browning as well. I’ve noticed that a greased silicone baking pan works better than an ungreased one.