Marbled blueberry-lemon layer cake
This was quite a cake of firsts:
1. First triple-layer cake to be blogged
2. First home-made preserve filling
3. First frosting using a sugar syrup method (sugar thermometer needed)
4. First go of torting and cutting the cake (to get an even-shaped cake)
Things that weren’t a first: distrusting part of the recipe (I think rightly, as we shall see), staining my fingers with food colouring (Sugarflair really is potent; my nails are still blue), eating too much icing. Recipe taken from Sky-high.
- 1 quantity blueberry preserve
- 1 quantity lemon buttercream frosting
- 8 oz butter, softened
- 2 cups sugar
- 2 tsp lemon zest
- 7 egg whites (crazy, huh?)
- 3 cups cake flour (take 3 cups plain flour, remove 6 tbsp, and replace with 6 tbsp cornflour)
- 4 tsp baking powder
- pinch salt
- 1 1/4 cups milk
- 2 tsp lemon juice
- 3 cups blueberries (300g I think)
- 3/4 cup sugar
- 2 tbsp lemon juice + 1 1/2 tsp lemon zest
- 1 tsp grated ginger
This is a lovely preserve, and rewarding to make, though I think you could substitute for blueberry jam if you needed speed. The subtlety of the lemon and ginger in the preserve if you make itself does go very well with the rest of the cake. Make sure you make it in advance as it needs time to cool. The above picture shows the preserve at start; by the time you finish you’ll have a consistency much like a thin jam. First puree the blueberries, and strain through a sieve to remove the skins (I ate them with yoghurt, it seemed a shame to throw all those antioxidants in the bin). Next, simply cook together this puree with the other ingredients, stirring over a low heat for around 30 mins until you have the jam-like consistency mentioned above. The total volume should have reduced to about a cup. Note, gentle readers, how I have switched to cup measurements. It is simply far easier than converting (and presto, you only have to wash a little metal thing.) It’ll only set you back about £4 from sainsbury’s. Once the preserve is ready, cool in the fridge (or freezer if you’re impatient)…you can make around 5 days ahead if you store in the fridge, but I wouldn’t leave for longer.
This recipe is fun because the blueberry preserve is used to fill the layers as well as in part of the cake itself, to create a cream/purple marbled effect.
Ok to make the cake. This is pretty simple as long as you don’t have a phobia of egg whites (of which there are zillions. Well, 7). Preheat the oven to 350 oF / 180 oC. Line three 8 inch (I actually used 7 inch, just don’t overfill) tins. Line them everywhere (sides and bottom) and grease the paper too. In one bowl, cream the sugar, lemon (x2) and butter till nice and light. Next add the egg whites a little at a time, beating in between each. In a separate bowl, mix the flour, salt and baking powder then again blend into the wet mixture in a few goes, alternating with the milk. Beat for a few minutes to ensure all is evenly mixed. Next, remove 1 cup of the batter and add to it 2-3 tsp of your preserve. Pour the remaining batter between the three tins then spoon dollops of the blueberry mixture into each. Drag a toothpick or knife through the tins to give a marbled effect. Bake in the oven for 25 mins (it took me around 15 minutes longer, but that could be my lazy oven), until a toothpick inserted in comes out clean, and the cakes bounce back slightly. If they’re too bouncy, they’re a bit overdone. Leave to cool completely before taking off the papers.
- 1 cup sugar + 1/4 cup sugar
- 2 eggs*
- 12 oz unsalted butter, softened
- 2-2 tbsp lemon juice (and some icing sugar)*
- a sugar thermometer
I think this will be the beginning of several fussy buttercream recipes. The inner scientist for once got to take some joy however, as this icing requires a very precise heating of sugar to 238 oF and therefore the use of a snazzy sugar thermometer. The thermometer helps. In essence, heat together the sugar and water in a small clean saucepan, stirring, over a lowish heat until the syrup starts to boil. At this point (with thermometer in the mixture) stop stirring, and keep the syrup over the heat till the temperature reaches 238 oF. Use a pastry brush, moistened, to wipe any sugar crystals off the side of the pan if you need. As soon as it reaches 238 oF (the soft ball stage) turn the heat off. Meanwhile, beat together the two eggs (*NB1 I reckon the book is wrong and it should have been 2 egg whites. Why? A) my buttercream came out yellow and not white as did theirs and b) all the other merengue buttercreams use egg whites only. If you try my suggestion, let me know). Then carefully, drizzle in the syrup whilst still electric-mixing, pouring it in down the side of the bowl. Keep beating until the mixture is body temperature and fluffy. Finally, add in the butter, one tbsp at a time or so, still mixing all the time. Towards the end it will suddenly turn horrid, keep beating and it will end up like whipped cream. Mix in the lemon and voila! NB2: I did find this a bit too buttery. I would rather have less butter. I ended up adding about 1/2 cup icing sugar and a bit more lemon juice to try and balance it. [Alternatively to all this make some normal buttercream and add lemon juce].
Nearly there! Finally, to assemble. I was excited to do my first torting for this cake. This is the art of cutting/shaving off the top of a cake to make it vertically level, or if you did what I did, to cut a thicker cake in half. I had only two tins, so made one shallow, and one deep cake, then cut the deeper on in half. The torting monster is a bit like an oversized cheese cutter, with a thin wire to cut. I think it’ll be very handy come wedding-cake making time…
Take the three layers, and begin by placing the first, cut/flat side up (to give an even layer). Spread half the preserve over one layer, place the middle tier on top, then repeat. Finish by placing the final tier flat side-up. For added erm sophistication (or if you’re a bit peckish) you may now proceed, to shaving off the sides, to make sure each layer is entirely flush with the other (see below right picture). The shavings are perfect taster-sizes. It is vital, as we all know, to check that one’s cakes are not poisonous before serving to a crowd. Try not to get too carried away however in your concern, or you may end up with a 4″ diameter cake. This is not an Italian leaning tower layer cake, after all.
Finally! Take the buttercream and frost the cake. If you have time, apply a thin crumb coat first everywhere, leave for 30 mins in the fridge to set, before applying the second coat. Smooth with a pallet knife or finger. To decorate, take some of the leftover icing (you will have too much) and colour it purple, or leave natural – and use to pipe a pattern round the edge. Garnish with blueberries.