Cakes & Cupcakes

Death By Chocolate Cake

Rich, incredibly moist chocolate cake layers made with REAL chocolate and paired with a silky chocolate frosting. This decadent death by chocolate cake is for every chocolate lover. Inspired from our favorite Costco cake that is now discontinued! 

Costco Chocolate Cake Copycat

This death by chocolate cake was inspired by our favorite chocolate cake from Costco that was discontinued recently. We loved the moist rich cake layers with that silky, fudgy frosting. This recipe is now our favorite official replacement and is requested multiple times a year for Father’s Day, birthdays, family gatherings, etc. It’s the ultimate crowd pleaser, so easy to make, and so many simple fun ways to decorate.

How to convert recipe to cupcakes and more

This chocolate cake recipe works for multiple sizes of cakes. The recipe is written for 3 – 8″ cake layers, but could be made into 2 – 9″ cake layers, cupcakes, or sheet cake if you’re feeding a crowd.

CUPCAKES: Line muffin tin with liners and fill about 3/4 way full. Bake for 18-21 minutes at 350 degrees and it makes about 24 cupcakes. 

SHEET CAKE: Line a half sheet baking pan with parchment paper, spray and pour batter. You can use it as a large sheet cake, or flip and cut in half to layer like a classic two layer sheet cake. 

9X13 PAN: Spray pan or line with parchment paper and fill about half way. You will only need half the amount of frosting for this option. Just remember to alter your baking time to match a different size pan. 

Can I make this ahead?

YES! This is a great recipe to make ahead, especially if you don’t want to be making it the day of an event. A lot of readers have told me they enjoy it on day 2 just as much or even more as day 1! To start, you can make the cake layers ahead of time, wrap well in plastic wrap and freeze or leave on the counter for one day.

Alternatively, you can assemble the whole thing with frosting one day in advance and store in fridge. You can also freeze a fully frosted cake for 30 minutes and then wrap well in plastic, giving frosting a chance to set so it doesn’t stick to plastic. Transfer to fridge for slow thawing, remove the plastic wrap, then transfer to the countertop. The cake layers stay fresh in the freezer for up to 3 months.

chocolate cake slice on white plate

Decorating Ideas for Death by Chocolate cake

There are endless ways to decorate this classic chocolate cake. Some ideas we’ve done:

  • Ganache with chocolate shavings on top
  • Rustic offset spatula lines 
  • Costco chocolate cake copycat (picture below; decorated by my talented niece!)
  • Mini chocolate chips covering the whole thing (easy fool proof way to jazz it up!)
chocolate cake with slices
chocolate cake on white stand

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If you make this recipe, make sure you tag @loskitchenco on Instagram and leave a comment below! You can also save for later by clicking the ‘Pin Recipe’ button on the recipe card. Happy baking! 

Death by Chocolate Cake

Lori Vaughn
Rich, incredibly moist chocolate cake layers made with REAL chocolate and paired with a silky chocolate frosting. This decadent death by chocolate cake is for every chocolate lover. Inspired from our favorite Costco cake that is now discontinued! 
5 from 7 votes
Prep Time 45 mins
Cook Time 25 mins
Total Time 1 hr 10 mins



  • 2 ¼ cups all purpose flour spooned and leveled, NOT packed
  • 2 cups sugar
  • ¾ cups dutch processed cocoa
  • 1 tsp baking soda
  • 1 tsp baking powder
  • 1 tsp sea salt
  • ½ cup sour cream or greek yogurt
  • ½ cup vegetable oil
  • 4 oz high quality dark chocolate
  • 3 large eggs
  • 2 tsp vanilla extract
  • 1 cup buttermilk*
  • 1 cup hot water or brewed coffee for more enhanced chocolate flavor


  • 1 1/2 cups unsalted butter
  • 8 oz cream cheese, room temp
  • 1 tbsp vanilla extract
  • 5-6 cups powdered sugar sifted
  • 1 1/2 cups dutch processed cocoa sifted
  • ¼ cup heavy whipping cream
  • 1/2 tsp salt

Ganache (optional)

  • 1 cup dark chocolate chips
  • ¾ cup heavy whipping cream



  • Preheat oven to 350° F. Grease three 8" cake rounds, line with parchment rounds (to make it easy to release), and spray again.
    (You can also make as four layer 6" cake, two 9" cakes, a sheet cake, or cupcakes - just adjust baking time)
  • In a large bowl or stand mixer, whisk together the dry ingredients - flour, sugar, cocoa, baking soda, baking powder, salt, and powdered buttermilk if you're using the powdered form.
  • Melt the chocolate in 20-30 second bursts in the microwave. It's done when the chocolate is almost completely melted, but not all the way. Stir together until all of it is melted and smooth. Set aside to cool down.
  • Whisk together the wet ingredients (sour cream, oil, eggs, vanilla, buttermilk, hot water, and melted chocolate) in a separate bowl. Then combine with the dry ingredients.
  • Mix together well until combined. Just don't over mix as that can lead to a crumbly cake.
  • Pour into prepared cake pans.
    (I did 4 layers above for a thinner and more stacked look). You can also do two 9" pans, four 6" layers, or 24 cupcake liners. Bake for 22-26 minutes. The cake is done when the toothpick comes out with moist crumbs on it. Transfer to cooling racks when done.


  • Beat the butter and cream cheese for about 2 minutes.
  • Slowly add the sifted powdered sugar and cocoa powder intermittently with the heavy whipping cream. Add the vanilla and salt. Add more cream as needed to get a soft consistency.
  • Beat the frosting for about 2-3 minutes.

Ganache (optional)

  • Heat up the heavy whipping cream in the microwave for about 30-45 seconds till hot. Pour over the chocolate chips. Cover and rest for a couple minutes to let it begin to melt the chocolate.
  • Whisk together the chips and ganache until smooth. Pour it into a drip bottle or use a spoon to add a drip to the cake.
  • If the ganache is too runny, let it cool longer. If it's still runnier than desired, you can add additional melted chocolate. If it's thicker than desired, add a little more warm heavy cream and whisk together.


  • Trim cake layers if needed to help achieve nice even layers.
  • Spread a small amount of frosting on a cake board (this will act like a glue for your first cake layer). Then place your first cake layer down.
  • Add an even layer of frosting, top with a cake, layer, add the layer of frosting, then add your last cake layer.
  • Apply an even, thin layer of frosting around the entire cake. Leave as is if frosting a semi-naked cake. Otherwise, place the cake in the freezer for about 15 minutes to create your "crumb coat".
  • Spread remaining frosting around the cake and garnish, drizzle ganache if desired, and pipe as desired.**


*You can use powdered or real buttermilk. If using powdered, follow the instructions of powder vs water ratios on the package. Add the powder with the dry ingredients and the water with the wet ingredients.
**To achieve a smooth even layer, I used an ateco cake scraper and icing spatulas. I also LOVE using parchment liners for my cake pans along with spraying non stick. No sticking every time! 
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1 year ago

5 stars
Loved this cake! It was so moist. It was to die for, Made it for Father’s Day and my husband loved it.

1 year ago

5 stars
This is the best chocolate cake I have ever made and ever tasted! I made it for my dad’s 70th birthday celebration, and every single person raved about it. They wanted to know where I got it. Not only did it taste amazing, but I have also been working on my cake decorating skills which most of them did not know about, so when they saw and tasted this cake, they all kept talking about how it is the best cake they ever had. They didn’t believe I had made it. Heehee! So good! It’s the perfect chocolate and sweet, not too sweet, just perfect! I think this is a combination of the coffee in the cake batter,as well as the cream cheese in the frosting. It counters the sweetness just perfectly to give you a variety of flavor and the perfect sweet richness without being overpoweringly sweet. Make this now!

1 year ago

Hi there! I want to make this for Christmas. If I halve the recipe would you make the batter with 2 eggs instead of 3? What are your thoughts on that? Thanks!

1 year ago
Reply to  Christi

5 stars
I made a 3 layer 8 inch one with 2 eggs and worked perfectly! It’s an amazing cake

Beth Farnsworth
11 months ago

5 stars
One of the best chocolate cakes I’ve ever made!! The frosting was amazing and the cake super moist! I added a tsp of Pero with the hot water and added raspberry filling in the frosting layers!

10 months ago

Where did you get your cake stand?

9 months ago

What kind of chocolate do you use for the sides if you want it look like the Costco cake?

7 months ago

5 stars
I made this for dessert last weekend for guests coming over. It was dense, moist and chocolatey. Absolutely loved it!

Natalie K.
Natalie K.
5 months ago

5 stars
My cake turned out absolutely perfect – moist, nice crumb, even top, just gorgeous. I used a different frosting but this cake is dead-on to the Costco version.

3 months ago

5 stars
By far the best chocolate cake I have ever made. It always gets rave reviews!

Kate S
Kate S
1 day ago

This cake was amazing. I get to Costco cake every year for my birthday and this was just as good. I love how she wrote this recipe and included the different pants sizes, that was so helpful! I will say this cake was 1000 times better after being refrigerated. I felt like the layers and texture were better instead of just kind of being all the same. Such a good recipe, thanks for sharing.