It is the time for a very special birthday, requiring, of course, a cake, and for the birthday boy only chocolate cake hits the spot. As usual, I wanted to try something different so I was casting around for a few ideas.
In my kitchen I have a ‘sundries’ drawer (not to be confused with the ‘junk’ drawer). It’s where I keep instruction manuals for kitchen equipment and, often, recipes that I’ve printed off the internet. I’d obviously been looking for chocolate cakes previously as I found 3 different cake recipes in there, an ‘Ultimate Chocolate Cake’ (albeit a different on from the one I’ve already written about-see The Ultimate-Chocolate Cake-and not as ‘ultimate’ in my opinion!), a ‘Fudgy Dark Chocolate Cake’ and something called the ‘Brooklyn Blackout Cake’-this latter one in particular intrigued me.
I think I’d put this in the drawer because it called for two ingredients that I had problems finding-buttermilk and espresso powder. Now buttermilk I have sorted out, it’s relatively easy to make by adding lemon juice or distilled white vinegar to milk (1 tbsp to 250 ml milk) but espresso powder might be more of an issue in rural Nova Scotia. It’s become the thing to add espresso to chocolate-flavoured things, not to add coffee flavour as such but because it is supposed to intensify the chocolate flavour. Well, anything to intensify chocolate flavour is a good thing by me! Still, would I find espresso powder here in the back of beyond? I would try on line.
Yes, there was espresso powder on Amazon.ca. I wasn’t sure what sort of powder to get so looked at baking espresso. My jaw nearly hit the keyboard when I saw the prices-the cheapest was over $30 for a very small jar of powder, going up to $90-now, I really couldn’t justify that! I thought I’d have a cursory glance in the coffee aisle at our local supermarket, not expecting much, and actually found some. It’s Nescafe, so maybe not the best quality as compared to the $90 stuff, but was only $11 for a large jar (and I even found a smaller jar for only $8 in our other supermarket), so much more reasonable.
So, I had much of the necessary for the Blackout cake. The recipe is British, in fact I think it is from the BBC Good Food website, and so it calls for fancy things like muscovado sugar-that, I knew, I wouldn’t find here but apparently the best substitute is dark soft brown sugar, which I did have. The cake itself was sorted.
The Blackout cake recipe used a chocolate custard as filling and topping. This was interesting and I’d definitely like to try it out, but maybe not when we had guests coming for dinner and the cake had to work. Maybe the frosting from the Fudgy Dark Chocolate Cake would combine well? I’d give it a go.
As mentioned, this is a British recipe and the metric measures are the most accurate. I have made an attempt to translate to imperial measures but daren’t try for cups!
| 140 g/5 oz unsalted butter, plus extra for greasing the cake pans * |
| 100 ml/ 3.4 fl oz vegetable oil |
| 140 g/ 5 oz buttermilk** |
| 100 ml/ 3.4 fl oz coffee, made with 3 tsp instant espresso powder*** |
| 2 large eggs, at room temperature |
| 1 tsp vanilla extract |
| 250 g/9 oz all-purpose (plain) flour |
| 250 g/9 oz light muscovado or dark soft brown sugar**** |
| 50 g/1.8 oz cocoa powder |
| 1 tsp bicarbonate of soda (baking soda) |
| 2 tsp baking powder |
| ¼ tsp salt |
*I used soft margarine to grease the pans
**buttermilk made by adding 1 tbsp lemon juice to 250 ml (1 cup) whole milk and leaving to stand for 10 minutes, then weighed before use
***original recipe called for 1 tsp of powder in 100 ml water. Instructions on the jar said 1-2 tsp in 50 ml, so I followed that. This may depend on the brand of espresso used. I also made up the coffee in advance and allowed it to cool before adding it to the mixture.
****I used dark soft brown sugar.
There are quite a lot of ingredients and I found it useful to measure everything out before starting.
I also got my cake pans ready beforehand. The recipe calls for 2 x 8 inch/20 cm sandwich tins, greased and with the bottoms lined. I like to use linings on the sides, too. Because I do, I can use soft margarine to grease my tins.
Preheat oven to 350˚F/325˚F convection/180˚C/160˚C fan/Gas 4
Place the butter in a saucepan over medium heat and allow to melt gently, remove from heat as soon as it is melted.
Add the oil, buttermilk, coffee, eggs and vanilla, beat to combine. I found a balloon whisk worked well.
Set the wet mix to one side.
Place all of the dry ingredients in a large bowl and whisk to combine. Note that I found that the dark soft brown sugar had a tendency to clump together, so I ended up sifting the partially-mixed powder through a sieve into a separate bowl to reduce the lumps. It didn’t work to sieve it in advance of whisking though, it worked best to mix, whisk, sieve then whisk again. This might not be as much of an issue if you use muscovado sugar.
Pour the wet ingredients into the dry and mix well using the balloon mix. It will look lumpy initially but will very soon mix to a smooth batter. This really was remarkably easy and quick to do.
Separate the batter equally between the two cake pans and smooth the tops.
Bake 20-30 minutes, until the cakes are risen and a tester comes out clean. Note that I baked my cakes at 325˚F convection and they took close to 30 minutes. Remove from the oven and leave to cool in the tin for 10 minutes.
After 10 minutes, remove from the tins and leave to cool completely on a wire rack. Now, this is a quite crumbly soft cake when warm, with a nice soft crumb, so don’t do what I did and try to put it on the rack ‘top up’!
Yes, that wasn’t going to glue together again! Luckily, I had enough of everything to start again and, an hour or so later, I had 3 cake sandwiches cooling on racks. It really is a quick and easy cake to make, once you have every ingredient collected together and weighed out.
Now for the fudge frosting. This was intended to layer the cakes and then cover the top and sides.
| 100 g/3.5 oz unsalted butter |
| 200 ml/ 6.8 fl oz double cream, heavy cream or whipping cream* |
| 3 tbsp clear honey |
| 200 g dark chocolate (70%), broken into small pieces |
| 2 tsp espresso powder |
| Icing sugar (powdered sugar/confectioner’s sugar), to taste |
*I used whipping cream
The original fudge frosting recipe was for 50g butter, 200 ml cream, 3 tbsp honey and 200 g dark chocolate. I thought I’d add the espresso powder to ‘boost ‘ the chocolate.
Heat the cream in a large saucepan until just boiling.
Remove from the heat and add the butter, chocolate and honey (and espresso if using). Allow to melt for 5 minutes.
Stir to combine but do not overmix. Allow to cool to just warm before using to ice the cakes.
Well, there were problems. Firstly, the fudge was not really sweet enough. maybe adding the coffee had made it more bitter than it should have been, but it certainly wasn’t a sweet icing. Secondly, it was still pretty runny. It wasn’t going to make a filling, let alone a frosting. It would end up as a puddle on the bottom of the cake. What to do?
Well, the recipe said not to overmix, but I thought that adding some additional butter, some icing sugar and beating it using the stand mixer might rescue it. I added an additional 50 g of butter and started the beaters going, I then started to spoon in icing sugar as it mixed, until I reached an acceptable sweetness and thickness (which is why it says ‘to taste’). I ended up with a nice fudgy icing. It still didn’t seem to me to be stiff enough to sandwich the cakes, but it would make a very acceptable icing. I’d need to do something else for the middle.
I remembered the swiss meringue buttercream that I’d made for last year’s birthday cake (see Celebration Time-Double Chocolate Devil’s Food Cake). That might work. By luck I’d also bought a bar of white chocolate, intending to use it to decorate the cake, but now it would come in handy to flavour the filling. This is why I called this a mash-up!
| 3 egg whites* |
| 250 g/8 oz/1 cup caster sugar (superfine sugar) |
| 175g/6 oz unsalted butter |
| 100 g white chocolate, broken into small pieces |
| ½ tsp vanilla extract |
| Pinch salt |
*I used commercially-separated free-range egg whites from a carton
Normally, I’d use freshly-separated egg whites but, for speed, I used some of those egg whites in a carton. These are pasteurized so I suppose even less of a potential health issue than using fresh egg whites. The whites are heated so safety is assured.
Using the bowl from your stand mixer (wipe out with lemon juice to ensure it is fat-free), standing over a pan of simmering water, add the egg whites and sugar. Whisk and heat until the sugar is melted. The temperature of the mixture can get to 140˚F/70˚C.
Remove from heat, transfer to the mixer and set beating. Add butter, in small cubes, to the mixture, as it is beating. Add vanilla extract. Beat for 10 minutes, until smooth and fluffy.
This is a very nice vanilla buttercream and could be used as is. However, I was going to amp up the chocolate, because that is what I do. I melted the chocolate in a double-boiler and then poured the slightly cooled melted white chocolate into the buttercream as it was mixing, and left it to mix for another few minutes. The resulting buttercream was allowed to cool for 10 minutes and then used to sandwich the cake.
I decided that two cake layers was quite enough (I froze the third layer for use at another time). With white chocolate buttercream filling and dark chocolate fudge frosting (and a sprinkle of chocolate vermicelli) it make a very acceptable cake, in the end.
I would definitely recommend the cake as a very good and easy-made sponge, worth keeping in the repertoire. I do think that the addition of the espresso boosted the flavour, although you certainly can’t taste coffee. Maybe I’ll have a go at that chocolate custard when I get the frozen layer out of the freezer.
I keep it in the fridge, but it cuts better if removed a little while before serving.
The Pudding Queen 
[…] not at all sure about this cake and was hunting out my recipe for Blackout Cake as a backup (see Bit of a Mash-Up-Blackout Fudge Cake). The sponge in this cake is very easy to make and is a lovely dark moist chocolate cake which […]
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