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Butter Rum Sheet Cake. This light and fluffy homemade yellow cake has rum baked in and is drenched in a butter rum sauce. Even though this cake is sized down it still has full sized flavor!
It’s the start of the Christmas baking season. So I’m bringing you this Butter Rum Sheet Cake. I guess it’s more of a small batch sheet cake, if that’s even a thing? One thing I can’t stand is wasting food. And as much as I love cake, and all the kids love cake, we just can’t ever seem to finish a cake.
Typically Butter Rum cake is made as a bundt cake. And even then, we just never eat it all. So I decided to make a sheet cake, smaller sized. I used an 8×8 pan, the typical size of a brownie pan. Which is the perfect amount of cake!
This cake is made completely from scratch. Getting a yellow cake to taste like a box mix is not the easiest thing in the world. So I turned to America’s Test Kitchen and their Yellow Cake recipe. They developed a method of adding the egg yolks to the batter and whipping the whites separately and folding into the batter to create the light and fluffy cake that we have come to expect from a box mix.
It is an extra step. But it is well worth it. You can of course skip it if you dare, but don’t expect the light and fluffy cake of your dreams.
The best part of the cake is the butter rum sauce that is drizzled on top. It’s basically just butter, rum and sugar. You want to pour it over the cake while the cake is still warm to allow the sauce to soak into it. It will leave a wonderful glazed top to the cake too.
Just a warning if you try to eat a piece as soon as you pour the warm sauce over the cake you may get hit with a super strong hit of rum flavoring. But it will mellow out as the sauce cools. Since we boil the alcohol and bake it in the cake, the alcohol will be removed. But the flavoring remains.
Butter Rum Sheet Cake
- 1½ cup cake flour
- ¾ tsp baking powder
- ⅛ tsp baking soda
- ½ tsp salt
- 1 cup white sugar divided
- 5 tbsp unsalted butter melted
- ⅓ cup buttermilk
- ⅓ cup rum
- 1 tbsp vegetable oil
- 1½ tsp vanilla extract
- 4 large egg yolks
- 2 egg whites
Butter Rum Sauce
- ¼ cup butter
- ½ cup white sugar
- 2 tbsp rum
- 2 tbsp water
- Preheat oven to 350°F. Spray an 8×8 baking pan with non stick baking spray. Set aside.
- In a large bowl combine the cake flour, baking powder, baking soda, and 3/4 cup of white sugar. Stir together with a fork to mix.
- In another medium size mixing bowl combine the melted butter, buttermilk, rum, oil, vanilla extract and egg yolks. Stir to combine.
- In a small separate bowl add the 2 egg whites. (you can discard or keep the other 2 remaining egg whites for another recipe, or an egg white omelet.) Beat the egg whites with a hand mixer until soft peaks start to form. Add the remaining 1/4 cup white sugar and continue to beat on high until peaks are stiff and shiny.
- Add the wet ingredients to the dry, stir until combined. Then fold in the egg whites gently.
- Pour the batter into the prepared cake pan.
- Bake at 350 for about 25-28 minutes or until the cake is cooked through. A toothpick inserted in the cake will come out clean, no batter.
Butter Rum Sauce
- Heat a small saucepan over medium heat. Add the butter and sugar. Allow the butter to melt and stir together with the sugar. Stir in the water and allow the mixture to come to a simmer, then remove from heat. Pour in the rum and stir together, the rum will make the mixture bubble.
- Allow to cool slightly.
- Using a toothpick poke holes into the top of the cake, then pour the butter rum sauce over the top of the still warm cake.
- Allow the cake to sit and cool for a few more minutes prior to serving.
Nutrition information is automatically calculated, so should only be used as an approximation.
Can you double this recipe to make a 13 x 9 cake
Yes you can! The bake time will need to be increased, I would estimate it between 35-40 minutes, please be sure to check it and use a toothpick inserted in the center to determine if it’s done or not.
Very good recipe. Thank you. It was so moist and perfect density. I used orange vanilla rum and it turned out amazing. Is now my family’s favorite dessert.
Hi, does the butter matter if it’s salted butter or unsalted butter? I have both kinds in sticks…. which is best?
Hi Carrie! I always use unsalted when I bake.
Can I make this cake the day before? How well does it hold up? The cake sounds great!!!
Hi Vicky! I love this cake! I’ve made it several times now and I want to say that it was still good the next day. Since it’s soaked in the rum sauce though, it can get slightly soggy, and I think on the third day was when it was too soggy. If you want to make it a day ahead I would maybe bake the cake, and do the warm sauce over it the day you want to serve it.
Do you use light or dark rum? This looks delicious!
Thanks so much! And I actually used a spiced rum I had on hand. Any light rum will work wonderfully in this recipe 🙂