This Montana Sheet Cake is our family’s version of the classic Texas Sheet Cake — a rich cocoa-buttermilk dessert that’s been passed down for generations. My mom got the recipe from a family friend, started baking it in the 1970s, and it’s been a family favorite ever since. Simple, nostalgic, and melt-in-your-mouth good — a Personal Rancher recipe straight from our roots.

It really is the best and fastest chocolate cake recipe ever! Start to finish in only 30 minutes, it’s a go-to dessert that is loved by all. 

Cut into bite size squares, this decadent almost fudge-like cake with just a hint of cinnamon is perfect for a no hassle dessert platter for any occasion. It's your last minute, what have I got on hand, I need a quick and fabulous dessert crowd-pleasing recipe.

Montana Sheet Cake 

Prep Time: 20 minutes

Cook Time: 10 Minutes

Cake Ingredients

• 1 cup (2 cubes) butter
• 3/4 cup water
• 2 cups flour
• 2 cups sugar
• 1 teaspoon baking soda
• 1/4 cup cocoa (unsweetened baking kind)
• 1 teaspoon cinnamon
• 2 eggs
• 1 teaspoon vanilla
• 1/2 cup buttermilk

Frosting Ingredients

• 1/4 cup cocoa (unsweetened baking kind)
• 1/2 cup (1 cube) butter
• 5 Tablespoons buttermilk
• 1 box powdered sugar (3 3/4 cups)
• 1 teaspoon vanilla

Bake@400 degrees   10-12 minutes

Cake Directions

1. Preheat oven to 400 degrees.
2. In a saucepan on stove over medium-low heat, bring 1/4 cup cocoa, 2 cubes butter and water to boil. Remove from heat.
3. In a separate mixing bowl (I use stand mixer), combine flour, sugar, baking soda & cinnamon.
4. Add cocoa mixture to flour mixture.
5. Mix with electric mixer.
6. Add eggs, vanilla & buttermilk. Mix until thoroughly blended.
7. Pour cake batter into a well greased and floured sheet pan (approx. 12”x17” pan).
8. Bake at 400 degrees for 10-12 minutes or until cake tests done.
9. While cake is baking prepare frosting.

Frosting Directions

1. In a saucepan on stove over medium-low heat, bring 1/4 cup cocoa, 1 cube butter and buttermilk to a boil. Stir while heating to avoid burning buttermilk. Remove from heat.
2. Add powdered sugar and vanilla.
3. Mix with an electric mixer until thoroughly blended.
4. Spread frosting over HOT cake.
5. Cool and cut into brownie size pieces. Serve.

This is hands down our favorite family cake recipe! My mom has made it for as long as I can remember. Always a hit, the Montana sheet cake cut into bite-sized squares has made an appearance at many a family get together and almost every party we’ve ever attended.

I love that it’s a from scratch recipe that is part of our pantry staples. You know those last minute, I need a dessert for a crowd moments? This is the recipe!

Tips & Tricks

Don’t heap the chocolate when measuring! This is unsweetened baking chocolate. Too much in cake or frosting will be bitter. Use a knife to level off measurements of unsweetened cocoa.

Buttermilk is the only ingredient in this recipe that I do not always have on hand. No buttermilk? No worries! Measure out milk, add vinegar to the milk to create a chemical reaction to mimic the buttermilk in the recipe. This method works in buttermilk pancakes too! Homemade Buttermilk Recipe Here

Watch the cooking time and test cake for doneness to prevent over baking and drying out cake. It’s easy to do when total bake time is 8-10 minutes.

This cake disappears fast! When I have leftovers, I flash freeze in a single layer then store in freezer (in container or freezer baggie). Bite size chocolate cake squares freeze and defrost well for even quicker, ready-to-go desserts.

Get creative with your toppings. Add your favorite chopped nuts and drizzle with salted caramel for a turtle version.

Enjoy this decadent Montana sheet cake recipe that will have you always signing up to bring the dessert!