The Alpha Bakers are tackling the Cran-Raspberry Upside Down cake this week. However, 'tis not the season for fresh cranberries in this hemisphere, and apparently Atlanta is not a market for frozen cranberries. I looked at 4 stores without success before moving on to the rhubarb variation, which is written for fresh rhubarb. Well, it's not the season for that, either, but I could get it frozen and figured I could work out how to handle frozen vs. fresh.
The main differences in the 2 variations (besides the obvious one of the fruit) is that the rhubarb is macerated a bit and the resulting juices are used in the topping. The cranberry adds lemon juice to the topping instead. If using frozen cranberries, Rose says to not defrost them, so I applied that to the frozen rhubarb and substituted some lemon juice for the non-existent juices from macerating. I used about 7 ounces of frozen rhubarb, the amount called for if using frozen (or fresh) cranberries.
Once I got through the decisions on how to work with frozen rhubarb, this began to look a little more like the quick-and-easy cake it's listed as in the book. The topping of butter, brown sugar, a bit of salt, and the lemon juice got boiled for a couple of minutes "until deeply amber"....but as I was using dark brown sugar, it pretty much started out deeply amber. I went by temperature, and was over the target in about 2 minutes. The syrup got poured into a springform pan and the frozen chunks of rhubarb, tossed with cornstarch and lemon zest, went on top.
Next up was the cake batter, which was indeed quick and easy--a butter cake with some sour cream. That got poured over the rhubarb, and then baked on a baking stone to help the topping caramelize. Baking done, the upside down part came in and I got to see how much stuck to the pan. Which was not too much, and the pieces of rhubarb could be picked out and stuck back on the cake. My cake sides weren't very pretty, as the crusty part fell off in places. Let's just call the whole effect "rustic". I used a seedless strawberry jam to glaze over the rhubarb, instead of the raspberry called for in the cranberry version.
The suggested accompaniment is a strawberry Italian meringue...which for me would definitely have removed this from the quick-and-easy category. But I don't really like Italian meringue much, and I hate making them (I always spin part of my hot sugar syrup onto the sides of my mixer bowl), so I went with the luxurious topping of strawberry whipped cream--basically whipped cream with some strawberry jam whipped in. I also stabilized mine with a bit of cream cheese, so it would hold ovenight and be sent off with sister-in-law for her Tickling Tech session Friday morning. She texted me a couple of comments: "This is delightful. It's so light. The whipped cream is heavenly." and "It looks heavy but doesn't fill you up." Another teacher asked for the recipe, and also asked how much I would charge to make one for her. Given my time crunch right now, the answer to that is "more than anyone would pay for a cake like this", but it was flattering to be asked.