Brooklyn Blackout Cake


I’d never eaten Brooklyn Blackout Cake before making it. I don’t think I’d even seen one outside of the Hummingbird Bakery cookbook. A little time with my good friend Google however, tells me this cake was made popular Ebinger Baking Company, opened in 1898 in, surprise surprise, Brooklyn. It’s name was supposed to have been solidified into popular memory when it became linked to the blackouts practiced in Brooklyn during World War 2 to help conceal the battleships leaving the Brooklyn Navy Yard.


I was a little dubious baking this cake, the sponge itself didn’t seem anything special, I couldn’t envision how the gloopy, thick custard could taste of anything other than corn flour. I am happy to admit I was very much mistaken. This cake is gorgeous. The custard becomes gloriously sticky and fudgy. It sticks to your teeth, and leaves crumbs all around your mouth, the way a good chocolate cake should. Three rich, chocolaty, fudgy layers of happiness. Some ended up smeared around the face of a beautiful, just turned one, little girl I know. Could there be a better seal of approval for any cake?


This cake is listed as being one of the more difficult in the book. Whilst I didn’t find it difficult as such, it is strange, and the custard that fills and tops the cake is unlike any icing I’ve made before. It takes a bit of beating to get it mixed together. As you attempt to mix in the corn flour you’re reminded of the school experiment about the properties of corn flour – the liquid that turns solid as soon as you bash it. How the heck do you get the water into that much corn flour when it keeps fighting back?! At times it defiantly feels a lot like fighting a losing battle. One more note on that pesky custard, when I cooled it in the fridge it formed a thick skin over the top. Don’t make the mistake I made of thinking you can beat the skin in. You can’t. You’ll just end up with tough, gluey lumps you’ll spend an age picking out. Save yourself a lot of time and hassle and just skim it off before you ice your cake.

Brooklyn Blackout Cake


(Adapted from The HummingBird Bakery)


For the Cake

100g unsalted butter, at room temperature
260g caster sugar
2 eggs
1/4 teaspoon vanilla extract
45g cocoa powder
3/4 teaspoon baking powder
3/4 teaspoon bicarbonate of soda
a pinch of salt
170g plain flour
160 ml whole milk

For the chocolate custard
500g caster sugar
1 tablespoon golden syrup
125g cocoa powder
200g cornflour
85g unsalted butter
1/2 teaspoon vanilla extract


Preheat your oven to 170C/350F.

If you have them, line three 20cm tins with greaseproof paper. I only had one tin so baked the cakes in batches, washing out, relining and reusing each tin as I went along.

Cream the butter and sugar together until pale and fluffy.

Add the eggs, one by one, beating well into the mixture each time. Beat in the cocoa powder, baking powder, bicarbonate of soda, salt and vanilla extract. Finally, beat in half the flour, then the milk, then the rest of the flour. Divide your mixture into three tins, or weigh out a third if you’re having to re-use your tin. Smooth the mixture down with a knife or the back of a spoon.

Bake each layer for about 20 minutes.

Leave to cool for a few minutes in the tin, then turn out onto a wire rack to cool completely.

Meanwhile, make the custard.

Put the golden syrup, sugar, cocoa powder and 600ml of water in a heavy based saucepan. Bring to the boil, stirring occasionally.

Meanwhile, mix together the corn flour, with about 150 – 200ml of water. You should be left with a thick paste. Add the water slowly, and use a little less if you need to.

Whisk the cornflour into the hot sugar mixture. Bring it up to the boil, whisking constantly, and keep cooking it until it’s really thick.

Stir in the butter and vanilla extract.

Put into a bowl, cover and cool in the fridge until very cold and very firm.

Before you put the cakes together, slice a thin layer off one of the layers. Blitz it up in the food processor to form cake crumbs. These will decorate the cake.

Cover one layer of the cake with about a quarter of the custard. Add the next layer, and cover with another quarter of the custard icing. Finally, add on the final layer and cover the top and sides with the remaining mixture. Press the crumbs all over the top and the sides. I achieved this by sort of throwing the crumbs towards the side of the cake with the palm of my hand, and tapping them on to keep them in place. There’s probably a better way of doing this, if you know one, please do let me know!

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