I saw these on Pfiel and Holding, I was thinking they'd be great for ice cream cakes, but it sounds to me like you can use them instead of pans for baked cakes as well and it seems interesting... but weird. So I'm curious, does anyone use these and if so, how?

I have an adjustable size cake ring/pastry ring that I use, but I don't bake in it. Basically I use it for a mold.

I mostly use it for bavarians, black forest cakes, and that type of thing. I line it with acetate ("cake collars"), then adjust size to fit cake diameter tightly.

A "simple" set up would be to put a layer of cake on the bottom, with the pastry ring fitted tightly to it. Then top with a bavarian cream made with gelatin so that it sets firm. Chill, then top with ganache.

You can do all sorts of fun stuff, like paint the cake collar with melted chocolate, push fruit up to the sides, wrap the bottom of the cake in a jaconde, layer different types of mousse so you have a "striped" affect, etc.

I have an adjustable one too that I adore! It's great for any of those HerBoudoir mentioned! I love decorative jacondes! In school we also made a mudslide torte...with a rice crispy bottom I think. Another really unique one was a baunkuchen torte that looked as though it had a wood grain to it. It lends easily to alot of novelty and variety!

i have one too.... i use it for mousse cakes and have tried baking in it too. I line it with parchment paper but u need to make sure there r no gaps or else ure batter will leek. Its gr8 for mousse cake but i wont really recomend it for baking... HTH

what is it? I don't get it . Can you show me pictures of your finished cakes?

I have tons of sizes. I use them for all sorts of things. Baking, building cakes in (especially good for mousse cakes), frozen mousses, etc. I love them! So versatile.

here's a link so one distributor for any who don't know. It's just a steel ring:

http://www.bakedeco.com/static/list/cake-rings.htm

They are basically a frame w/out a bottom.
I used them for 'dowels' in many of my wedding cakes until a couple of wedding planners told me they hated having to cut a cake w/them in it as they have to push the cake out of the ring

Yes, then can be used to bake with IF you have perfectly level pans for them to sit on. Many times the b atter leaks out before it set up making the pan a mess and the cake not as tall as yoiu want.

what is a mousse cake?

It's a cake made with mousse! lol Seriously though there are many different types of mousse cakes. Some are simply molded frozen "cakes" made of mousse, others are thin layers of cake with mousse layers in between (more than just a filling--the mousse is the main component of the cake), or a think layer of cake around the outside filled with mousse. You can have a fruit mousse cake (like a miroir). The possibility for a mousse cake are endless.

This first cake is a pate a cornet mousse cake which is a thin sheet of cake around the outside and the entire center of the cake is mousse. The second cake is a fruit miroir--peach mousse over cake. Both were built in cake rings.

OOOOO, Pink that gives me ideas!!! Think about how cool that would be!

Take a ring, make a sleeve out of acetate, and you could pretty much pipe ANYTHING on the sleeve with chocolate (white or dark), and then fill with a contrasting color of mousse, and voila instant dessert! Top with some flavored whipped cream and some fresh fruit!

Ohhhh the flavor combos that I could come up with, chocolate chip, cherry dark chocolate, peaches and cream, Oreo cookie, Moon Pie, Nutty Peanut Butter Chocolate, CHOCOLATE MINT!!!

Can you just imagine my voice getting louder with each idea? I am so excited, I can barely contain it. I think I need prefessional help some days.

I can actually "feel" the excitement in your post! lol the possibilities really are endless! With a little gelatin and/or some meringue you can turn almost anything into a molded dessert.