Petits Fours Perdus

What to do with leftover cake?  I don't mean leftover slices of cake (a non-problem that science tells us we can avoid), I mean the scraps that come from leveling cake layers, or occasionally, from carving out a hole for a manuscript to sit in.  With smaller scraps there aren't too many options (apart from just eating them, which is a perfectly acceptable solution).  Duff Goldman, of 'Ace of Cakes' fame, has started layering scraps in jars with buttercream and selling them online, which is a fairly clever way to recycle, boost profits and please an audience who would like a taste of what they see on tv.  Especially, that is, if you have profits and tv audience... but even if you don't it's still an idea.  The Wall Street Journal reporter was somewhat disturbed at the prospect of cake in a jar, and science (more science!) might back up his il ne sait quoi, but it seems pretty Pinterest-ready to me.  Alternatively I'm a big supporter of cake pops or cake balls, especially if you've got some leftover buttercream to go with the leftover cake.  Just crumble the cake, stir in some buttercream, roll into balls and dip in chocolate.  No mason jars required.

I had more than your standard excess of scraps after carving the Black Book of Cake, however; I essentially had a complete layer of cake.  This made me think that I wanted to use the layer as a layer, rather than crumbling it up or stuffing it into a jar.  As I also had a lot of leftover buttercream, I decided to make some petits fours.  I needed something to take to a party, and these were perfect because their size makes them look complicated, but done this way they are extremely easy.  I had stored the cake scraps in the freezer, so I removed the largest slab and let it thaw for a few minutes.  Next I split the layer (carefully, as it was already itself the top half of split layer), and then spread jam on the top of one half and buttercream on top of the other.  Don't forget to re-beat the buttercream before use so it is silky and easy to spread (and if it goes through the same scrambled-egg stage that it passed through when it was first made, don't worry - it'll come back).  Sandwich the layers together, flipping the buttercream layer over so that it is directly on top of the jam.  If you put the jam on top of the buttercream the jam will drag through the buttercream when the cake is cut.  This won't change the taste, of course (say what you want, science), but it also won't look as pretty.

Also in the name of beauty, the edges of the cake should be trimmed off.  After you have sandwiched the layers, smooth a layer of buttercream on top and pop it in the freezer for two or so minutes to set; this will make for sharper edges when cutting the cake.  Running your knife under hot water and then drying it before cutting will also make things cleaner and easier (like a hot knife through buttercream...), just remember to wipe it off with a towel between slices.  After the edges have been trimmed (and eaten), measure out your petits fours.  You can use a measuring tape to mark out even sections, but I just eyeballed mine.

Then decorate the tiny cakes!  I choose to colour some of the leftover leftover buttercream to make little rosebuds, which I practiced a couple times on my spatula before piping on the cakes because it had been awhile since I'd last made one.

You can also practice on parchment paper or on a plate, all you need is a petal tip and a piping bag.  The wider end should be on the bottom when piping, starting with a bit of pressure so the bud has some volume and lessening pressure as you swoop the tip around in a motion similar to writing a backwards '6' (this youtube video gives some idea).  To top the rosebuds off, colour a bit more buttercream green and plop it into another piping bag with a leaf tip.  If you don't have a leaf tip, trim the end of the piping bag to a point - this will create a leaf-like shape as you squeeze out the buttercream.  Squeeze with some pressure to form the base of the leaf, and decreasing pressure in a short, smooth upwards motion, pipe the foliage onto the rosebuds.

Ta da!  Petits fours: the French toast or Welsh rarebit of cake.