Since I wrote this post my rhubarb obsession has continued unabated; rhubarb based cocktails and raspberry and rhubarb smoothies are now regular feature in my kitchen. I had been mulling over the idea of turning the classic rhubarb and custard combination into a cake. At first I experimented with a tray bake type cake with small pieces of uncooked rhubarb incorporated in to the cake batter and the resulting cake topped with a custard style frosting. This was a perfectly acceptable cake but it just didn’t have the strong rhubarb hit that I wanted so went back to the drawing board and came up with idea of a classic sponge sandwich cake. I used my old-reliable sponge recipe1 to give me two lovely cakes.
While still warm I pricked the cakes all over with a fork and brushed on generous quantities of sugar syrup. This trick helps to keep cakes moist and delicious and ensures they keep for longer. I was torn between using rhubarb jam2 or baked fruit3 for the filling so I made both and decided to use both for a particularly decadent filling. I coated both cakes with my rhubarb jam and added a layer of custard buttercream to the bottom one. I used this buttercream recipe but cut it down to a third of the original recipe (1 pound of butter seemed like plenty). There are easier looking recipes out there involving custard powder but as custard powder is on my list of "things I don't approve of" (this list also features Rod Stewart and advent calendars with chocolates inside) I felt I had to make the effort. This buttercream is definitely worth the fuss involved; although it can't possibly be, it tastes light as well as delicious and it's not as sickeningly cloying as some frostings.
I then carefully placed the baked rhubarb on top (although looking at the photo it looks like I fecked it on there) and added the other cake on top. A considerable amount of custard buttercream on the top, a bit of smoothing and it was ready to go. I had a great idea at this stage to make some crystallised mint leaves to go on the top. As I was in the middle of packing for my holiday, planting out tomatoes on the balcony, cleaning the house and having a row with The Husband, it probably wasn’t the best time to try out a new culinary technique. Needless to say it was a complete disaster. Next time.....
I brought one of these cakes to work and it disappeared in record time. I had to make another one just so The Husband could try a slice. I will definitely be making this cake and might even get around to some fancy flourishes.
1 Sponge recipe: 6oz of caster sugar and 6 oz soft butter and ½ teaspoon of vanilla paste beaten with the mixer until light and fluffy. 3 eggs added one by one with beating and 6 oz of self raising flour folded in at the end. Divided between two greased and lined sandwich tins and baked at 190°C. In my oven it takes 19 minutes but it could be anything up to 25.
2 I made a batch of rhubarb jam using the recipe from Pam Corbin’s fantastic book Preserves: River Cottage Handbook No.2 but if you can’t be bothered, raspberry jam would probably work equally well.
3 I chopped up half a bunch of rhubarb into approximately 3 inch pieces, placed them in a baking dish, sprinkled over about a cup of sugar, covered with tinfoil and baked at 200°C for about 20 minutes until tender but holding their shape.
4 I actually used some lemon balm infused syrup I had in the fridge for cocktail making. 500g sugar in 250ml of water was heated until all the sugar dissolved. I took it off the heat and added a bunch of large lemon balm and left it to infuse for a couple of hours before straining it into a sterilised bottle which I now keep in the fridge. I warmed 200ml of this up in a saucepan and added some of the juices that had come out of the rhubarb as it baked to make my cake syrup.