Orange Marmalade Upside-Down Cake

I made a double batch of the Orange Marmalade (and yes, I know you're not suppose to do that, but I did), canned it in mostly half-pint jars (until I ran out), and it came out fantastic -I just have twice as much as I thought I would, NOT that that's a bad thing. This (click here) is what I definitely plan to do with some of it. Orange Marmalade Upside-Down Cake sounds to me like the perfect cake to bake in December.

The Cake Project: 60 Cakes in 60 Days. Need I say more? Cookies are the more usual December baking focus, but 60 cake recipes with stories from home bakers is a brilliant idea -any time of the year.