Grandma’s old-fashioned Texas sheet cake is a moist chocolate cake baked in a jelly roll pan and smothered with a rich, warm fudge frosting. It feeds a crowd and is a favorite for birthdays, potlucks, and cookouts all summer long!
More old-fashioned chocolate cakes:
Before You Get Started
A few things make the difference between a good Texas sheet cake and a great one:
- Use real buttermilk, not a substitute. The acid keeps the crumb tender and reacts with the baking soda so the cake rises right.
- Frost the cake while it’s still hot. The warm frosting soaks into the surface and sets like a fudgy ganache as it cools.
- Flatten any dome before you frost. A level top keeps the icing from running off the sides. Just press gently with a clean towel.
How to Make Texas Sheet Cake
This is a true from-scratch cake, but it comes together fast and it’s hard to mess up. The signature move is pouring the warm frosting over the warm cake, which is what gives it that glossy, fudgy top. All you need is one saucepan, one bowl, and a jelly roll pan.
Step 1: Boil the Chocolate Mixture
Combine the butter, shortening, water, and cocoa powder in a saucepan and bring it to a boil, whisking just until the butter and shortening melt.
Pull it off the heat. The shortening here is what keeps the interior light and soft.
→ Out of shortening? You can use all butter instead. The cake will still be delicious, just a touch denser.
Step 2: Mix the Batter
In a large bowl, whisk together the sugar, flour, baking soda, and salt.
Pour the hot chocolate mixture over the top and beat on medium speed for about a minute, then add the eggs, buttermilk, and vanilla and beat one minute more.
→ The batter will look thin. That’s exactly right. A loose, pourable batter is what gives this cake its signature tender crumb.
Step 3: Bake
Pour the batter into a greased 10×15-inch jelly roll pan and tap it on the counter a few times to release air bubbles.
Bake at 400°F for 20 to 23 minutes, until a toothpick in the center comes out clean.
→ If the top domes at all, gently press it flat with a clean towel while it’s warm so the frosting won’t slide off later.
Step 4: Make the Frosting While the Cake is Warm
The minute the cake comes out, start the frosting. Bring the butter, cocoa powder, and milk to a boil, just until the butter melts.
Off the heat, beat in the sifted confectioners’ sugar and vanilla until smooth. Sifting first is the easiest way to keep it lump-free.
Step 5: Frost the Hot Cake
Pour the warm frosting over the warm cake and spread it to the edges with an offset spatula. Frosting while both are warm is what lets it settle into that glossy layer instead of sitting on top.
Then set the cake on a wire rack and let it cool completely. The frosting firms up as it sits, almost like a ganache, before you slice it into squares.
⇢ Make it festive. Scatter about ¾ cup toasted chopped pecans over the hot frosting, or add sprinkles in seasonal colors for birthdays and holidays.
This cake is built for a crowd. One jelly roll pan cuts into about 24 small squares, so it’s a natural for potlucks, cookouts, and birthday parties. It travels well and holds at room temperature, and a scoop of vanilla ice cream never hurts.
Storage
Make Ahead: This is a great do-ahead dessert. Bake it the day before you plan to serve it, and it actually tastes better as it sits.
Store: Cover and keep at room temperature for up to 5 days, or in an airtight container in the fridge for 1 to 2 weeks. If your kitchen runs warm or humid, the fridge is the safer choice.
Freeze: Frost the cake, let it cool completely, then wrap tightly and freeze for up to 3 months. Thaw on the counter for a few hours before serving.
Frequently Asked Questions
Can I make this in a 9×13 pan instead of a jelly roll pan?
Yes. The cake will be noticeably thicker, so lower the oven to 350°F and add roughly 15 minutes to the bake time. Test the center with a toothpick, since a deeper cake takes longer to set.
My batter looks really thin. Did I do something wrong?
Not at all. This batter is meant to be loose and pourable thanks to the boiled butter mixture. Just pour it straight into the pan and it will bake up into that classic tender crumb.
Why didn’t my frosting set up firm?
The frosting needs to be poured while it’s hot and given time to cool fully before slicing. If it’s still soft, let the cake sit a little longer at room temperature, and check that you measured the confectioners’ sugar fully, since that’s what firms it into a fudgy layer.
More Old-Fashioned Chocolate Desserts
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Grandma’s Texas Chocolate Sheet Cake
Equipment
Ingredients
FOR THE CAKE
- ½ cup (1 stick) salted butter
- ½ cup shortening
- 1 cup water
- ¼ cup unsweetened cocoa powder
- 2 cups granulated sugar
- 2 cups all-purpose flour
- 1 teaspoon baking soda
- 1 teaspoon salt
- 2 large eggs
- ½ cup buttermilk
- 1 teaspoon vanilla extract
FOR THE FROSTING
- ½ cup (1 stick) salted butter
- ¼ cup unsweetened cocoa powder
- 6 tablespoons whole or 2% milk
- 16 oz confectioners’ sugar, sifted
- 1 teaspoon vanilla extract
- 1 cup chopped pecans (optional)
- Optional garnish: rainbow sprinkles
Instructions
FOR THE CAKE
- Preheat the oven to 400°F. Grease a 10 x 15-inch jelly roll pan and set it aside.
- In a saucepan, combine the butter, shortening, water, and cocoa powder. Bring to a boil over medium heat, whisking just until the butter and shortening melt, then remove from the heat.
- In a large bowl, whisk together the sugar, flour, baking soda, and salt.
- Pour the hot cocoa mixture over the dry ingredients and beat with an electric mixer on medium speed for 1 minute.
- Add the eggs, buttermilk, and vanilla. Beat on medium speed for 1 minute more. The batter will be thin and pourable, which is exactly what you want.
- Pour the batter into the prepared pan and tap it on the counter a few times to release air bubbles.
- Bake for 20 to 23 minutes, until a toothpick inserted in the center comes out clean.
- Set the pan on a wire rack. If the cake domed at all, gently press the top flat with a clean towel while it's warm so the frosting won't run off the sides. Leave the cake in the pan and make the frosting right away.
FOR THE FROSTING
- In a saucepan, combine the butter, cocoa powder, and milk. Bring to a boil, whisking just until the butter melts, then remove from the heat.
- Beat in the sifted confectioners' sugar and vanilla until smooth and glossy. Fold in the pecans, if using.
- Pour the warm frosting over the warm cake and spread it to the edges with an offset spatula. Add sprinkles now, if using. Set the cake on a wire rack and cool completely; the frosting firms up like a fudgy ganache as it sits.
- Slice into squares and serve.
Notes
- Don’t skip the buttermilk. Regular milk won’t work here. The acid in buttermilk keeps the cake moist and reacts with the baking soda to help it rise.
- Shortening swap. No shortening on hand? Use all butter. The cake will be a little denser but still delicious.
- Sift the sugar. Sifting the confectioners’ sugar before it goes into the frosting is the easiest way to keep it smooth and lump-free.
- 9×13 pan option. You can bake this in a 9×13-inch pan instead. The cake will be thicker, so lower the oven to 350°F and add about 15 minutes to the bake time. Test the center with a toothpick.
- Make it festive. Add ¾ cup toasted chopped pecans to the hot frosting, or scatter on colored sprinkles. Tailor the colors to the occasion, like orange and black for Halloween or red and green for Christmas.
- Make ahead. Bake it a day in advance (it tastes even better the next day), or freeze the frosted cake for up to 3 months.
Nutrition
Originally published in November, 2020, this post was updated in June, 2026.
I adore all your recipes and very thankful I can easily find them all! Thank you and God Bless you.
Thank you so much, Colleen!
Hi Blair, I don’t have a jelly roll pan , can I use a 9×13 cake pan?
Hi! Yes, you should be able to use the 9 x 13-inch baking dish, but the cake will be thicker so you’ll need to adjust the baking time. Hope you enjoy!
I followed this recipe exactly as it is, ( wich is extremely rare for me, because i typically do a lot of add-ins or substitutions), but it came out perfect! The only thing was the pan size Injust used a regular sized cake pan, so i just cooked it 15 minutes longer at 350, and it is to die for!! Thanks for sharing!
We’re so glad it turned out well for you, Noel! Thank you for trying it out and taking the time to leave a review.
I love the ingredients you gave and the instructions. Baked up beautiful, it looks amazing. I may have gotten carried away with the pecans, looks like a lot, but who doesn’t love pecans?
Thank you, Anne. Pecans are delicious! I hope the cake was a hit! 🙂