You catch the smell through the steam vent and suddenly you are starving. It’s like the whole kitchen just lit up with that deep chocolate scent that makes you wanna lick the air. You remember the last time you brought a cake to a party and got all those compliments well, this one’s gonna top that for sure.

There’s somethin about pressure cookin' this cake that works real good. You see, the steam cues and the valve hiss are like a little countdown to deliciousness. It’s quick, it’s easy, and it’s seriously tasty. You won’t believe it didn’t come from Costco itself.
When you cut into it, the texture is just right moist but not wet, soft but it stands tall. You gotta try makin’ this recipe next time you wanna impress with barely any fuss. Trust me, every celebration will want this cake in the spotlight.
What Makes Pressure Cooking Win Every Round
- Pressure cooking speeds up baking without drownin' flavors.
- The steam inside keeps the cake super moist and tender.
- Float valve and valve hiss give you perfect steam control without guesswork.
- The quick release helps avoid overcooking by gettin' steam out fast once done.
- Less heat in the kitchen means you can focus on makin' frosting or decorations.
Your Simple Ingredient Checklist
You only need some basic stuff that you probably have hangin' in your pantry already. Gather up two cups of all-purpose flour and two cups of granulated sugar. The rich cocoa powder, about ¾ cup, is gonna bring that chocolate punch you want.
Don't forget your leaveners, two teaspoons baking powder and one and a half teaspoons baking soda, plus a teaspoon of salt. For the wet side of things, you need one cup of buttermilk, half a cup of vegetable oil, two big eggs, and two teaspoons of vanilla extract.

Hot water gets stirred in to smooth the batter—about one cup is just right. And for the frosting, grab a cup of unsalted butter, half a cup whole milk, 12 ounces semi-sweet chocolate chips, four cups powdered sugar, and one more teaspoon of vanilla extract. Just these ingredients got you set for the whole thing from cake to frosting.
The Full Pressure Cooker Journey
First, you gotta preheat that oven to three-fifty degrees. Next, grease and flour a nine by thirteen inch sheet cake pan so the cake slides out easy. While that’s happening, sift together flour, sugar, cocoa powder, baking powder, baking soda, and salt in a big ol’ bowl.
In another bowl, whisk buttermilk, vegetable oil, eggs, and vanilla extract till combined. Slowly mix your wet stuff into the dry ingredients. Then slowly pour in your hot water, stirring gently till the batter's nice and smooth.
Now pour the batter into your greased pan. Pop it into the oven for 30 to 35 minutes. When you notice the toothpick comes out clean, it’s time to take the cake out and let it cool completely before frosting.
For the frosting, melt that butter and chocolate chips together till smooth. Stir in powdered sugar and milk, then add the vanilla extract. Beat it all till it’s light and fluffy. Spread this frosting all over the cool cake evenly and you’re set.
Valve Hacks You Need to Know
Keep an eye on the float valve, it’s your buddy during pressure cookin’. When it rises, it means pressure is building up just right. You gotta wait for the full valve hiss before you start timing your cook.
When it’s done, quick release is your best friend if you don’t wanna overcook. It lets the steam out fast, coolin' things down quicker. If you wanna keep the cake moist but don't wanna wait, slow release also works, but gotta watch it close so the cake doesn’t dry out.
Oh and don’t forget to tilt the valve gently when doing quick release so the steam shoots out safely. Rushing that part can make a mess or even burn you.
Your First Taste After the Wait
Cuttin’ into this cake feels like a mini celebration all on its own. The crumb is perfectly tender not crumbly or dry. You notice the rich cocoa flavor hits you first, then the sweetness from the sugar and frosting gets all playful on your tongue.
The frosting is silky smooth and not overly sweet, just right to balance that deep chocolate goodness. You find yourself wanting another bite, then another. It’s the kinda cake that brings smiles around the table and makes folks ask for your secret.

Seriously, this cake is a showstopper every time. You remember why you love makin' things in your pressure cooker when you taste this. It’s worth the wait, every single time.
How to Store This for Later
If you got leftovers, no worries. Wrap the cake real good with plastic wrap or keep it in an airtight container to keep it from drying out. You want that moisture locked in to save every bit of yum.
You can keep it out on the counter for a day or two if it’s covered. After that, stick it in the fridge and it’ll last about a week. Just bring it back to room temp before you eat so it tastes fresh again.
For longer storage, slice and freeze pieces wrapped well in foil or freezer bags. When ready, thaw at room temperature or pop it in the microwave for a few seconds.
Always keep the frosting covered good or it could get a bit crusty. This way, every bite stays just as tasty as the day you made it.
The FAQ Section You Actually Need
- Can you really bake a sheet cake in a pressure cooker? Heck yeah, with a pan that fits and watchin' the steam cues, your cake comes out great. Pressure cookers make it faster and moist. Check out our other pressure cooker recipes for more quick baking ideas.
- What’s the difference between quick release and slow release? Quick release lets steam out fast once done so your food doesn't cook more. Slow release takes time to lower pressure and keeps heat in longer for some recipes. Learn how to use the pressure cooker safety tips.
- How do I know when my pressure cooker is ready? Wait for the float valve to pop up and you hear the valve hiss. That means it’s pressurized and cook time begins.
- Can I use regular milk instead of buttermilk? You can, but add a bit of lemon juice or vinegar to sour it a bit so it acts like buttermilk. That helps your cake’s texture.
- Why is my cake coming out dry? Maybe you’re overcooking or not enough liquid. Check steam pressure and try slow release next time so moisture stays in.
- Can I double the recipe? You can try but use a bigger pan and cook time might change. Better to do separate batches if you can.

Food Trends Costco I Will Be Bringing This Copycat Costco Sheet Cake To Every Celebration (& You Should Too)
Ingredients
Ingredients
- 2 cups All-purpose flour
- 2 cups Granulated sugar
- ¾ cup Cocoa powder rich
- 2 teaspoons Baking powder
- 1.5 teaspoons Baking soda
- 1 teaspoon Salt
- 1 cup Buttermilk
- ½ cup Vegetable oil
- 2 Eggs big
- 2 teaspoons Vanilla extract
- 1 cup Hot water to smooth batter
- 1 cup Unsalted butter for frosting
- ½ cup Whole milk for frosting
- 12 ounces Semi-sweet chocolate chips for frosting
- 4 cups Powdered sugar for frosting
- 1 teaspoon Vanilla extract for frosting
Instructions
Instructions
- Preheat the oven to 350 degrees Fahrenheit.
- Grease and flour a 9 by 13 inch sheet cake pan for easy release.
- Sift together flour, sugar, cocoa powder, baking powder, baking soda, and salt in a large bowl.
- In another bowl, whisk buttermilk, vegetable oil, eggs, and vanilla extract until combined.
- Slowly mix the wet ingredients into the dry ingredients.
- Gradually pour in the hot water, stirring gently until the batter is smooth.
- Pour the batter into the greased pan.
- Bake in the oven for 30 to 35 minutes or until a toothpick comes out clean.
- Remove the cake from the oven and let it cool completely before frosting.
- Melt butter and chocolate chips together until smooth for the frosting.
- Stir in powdered sugar and milk, then add vanilla extract.
- Beat the frosting mixture until light and fluffy.
- Spread the frosting evenly over the cooled cake.




