It is made to take heat but I don't know it if takes heat as high as an oven. I would try it with a small amount of water in the bottom just in case it cracks.
My suggestion would be to use it as a planter with some kind of an inset so that water can drain down so as not to rot a plant since you cannot drill a hole in it or it will crack for sure.
Maybe make some quilted flowers for a bouquet that doesn't neet to be watered.