Chocolate Cake. Chocolate Custard. Chocolate Buttercream.
Covered in moist cake crumbs the ultimate Brooklyn Blackout Cake has just arrived

Invented during WW2 by a Brooklyn bakery named Ebinger’s.
In recognition of the mandatory blackouts to protect the Brooklyn Navy Yard
But after the war, the name and the cake persisted and became a signature offering popular with Brooklyn residents.
While that history is interesting, I think my explanation is more fitting :
I’m pretty sure you may just blackout after eating this cake!

Notes for Success
Cornstarch is a very difficult ingredient to measure consistently with a volume spoons measure
So while I list both measures below I cannot stress enough how the grams measure with a scale is going to give you the best results.
Many times people have complained that their custard is like rubber and they don’t know why!
Since I only used three layers for the cake the fourth layer was broken up for the cake crumb coating!
If you prefer to bake in 8″ cake pans just divide the batter evenly amongst 3-8″ cakes, your cake will be much thinner layers this way
With the third layer being used as the crumble.
Acetate cake strips are my preference for building a cake like this so I can pour the hot custard into the layers
Rather than cooling the custard and spreading it in later.
This method allows the custard to set in the cake for a very smooth clean layer
And the custard won’t break down upon slicing as it could when you allow it to set in a bowl, then spoon it into the cake as you build
Optional of course, but I guarantee once you try my method you won’t go back!

Of course you can build the cake traditionally with cold custard and a buttercream dam around the edges.
But either way you cannot ice this cake until it is completely cold and set.
Then give it a thin crumb coat of chocolate buttercream and slather on those big fluffy, moist chocolate cake crumbs!
CLICK HERE FOR THE FULL YOUTUBE VIDEO TUTORIAL FOR HOW TO MAKE THE BROOKLYN BLACKOUT CAKE


Brooklyn Blackout Cake
Ingredients
For the Chocolate Custard:
- 2 cup Plant Milk (474ml)
- ½ cup Granulated Sugar (100g)
- 4 Tbs Cornstarch *see notes (32g)
- 2 Tbs Cocoa Powder
- 2½ ounces Semi-Sweet Chocolate (½ cup chopped)
- 1½ Tbs Vegan Butter (21g0
- 1 teaspoon Vanilla Extract (5ml)
Instructions
- Prepare your cake pans with grease & parchment paper liner & preheat the oven to 350°F The recipe below for chocolate cake will make either 3-8" layers OR 4-7" layers. Which ever size you choose you must use one of the layers for the cake crumb coating
- First prepare the cake recipe as per the instructions on that page.
- For the 7" layers, the oven temperature will stay at 350℉ but will probably take about 25 minutes to bake, always check at around 18 minutes just to see how it's going
- While the cake is baking prepare the cocoa paste for the chocolate buttercream by combining the hot water with the cocoa powder, whisk smooth then set aside to cool.
- Prepare the buttercream recipe according to the instructions on that recipe post, & at the last stage of mixing add the cooled cocoa paste. Mix well.
- Prepare the custard by combining plant milk, sugar, cocoa powder & cornstarch in a medium sauce pot over medium to high heat & bring to a boil stirring constantly to avoid scorching the bottom .
- Once it starts to bubble remove from the heat & add the vegan butter & the chocolate, stir to melt evenly
- Add the vanilla extract stir to mix well.
- Set up your cooled cake layers with the acetate strip & pour the custard into each layer *see video instruction for more clarity.
- Refrigerate the cake until set and then ice with chocolate buttercream
- Use the remaining cake layer to break up into large crumbs to stick onto the buttercream icing.
Video
Notes

Hi Gretchen,
I’m not sure if the cocoa powder for the custard must be natural or Dutch. Which one do you recommend? Thanks.
for custard it doesn’t make a difference
Hi , Can’t thank you enough for this recipe. I tried your recipe – the test was perfect. Just the way I like it. Thanks once again.
YAY! thankyou for the feedback!
Hi….. Cake design are awesome, Your Cake Recipe is really True.
Thanks For Sharing information.!!!…………….
I love this cake! Thank you. I made it for my vegan bakery and it’s a hit! I was wondering if I missed it…do you give a baking time for 3 7″ chocolate cake layers? I only saw it for the sheet cake (40 min). I baked mine in 3 8″ pans in a convection oven for 25 min.
Hey great! Thanks for the comment! I will update the post thanks!
Hi Gretchen: Where doyou purchase the acetate cake strips. Thank you
Hi Paula I link to it in the article but here it is again
CLICK HERE
Did I do something wrong? I made the cakes following the “One Hour ~One Bowl” chocolate cake recipe, but there was only enough batter for two 8″ rounds, not 3. Was I supposed to make the cake layers thinner for this recipe, or should I have 1.5’d it?
Regardless, the cake turned out super delicious, even without the crumb coating!
What height of acetate is the most useful to have on hand?
Thank you for sharing!
NIce Recipe! I will definitely try this cake recipe!
I made this for New Year’s Day and OMG was it amazing! Great way to start my goal of getting back into baking more often in the New year!
YAY! Thanks for the feedback!