This White Texas Sheet Cake recipe is your new best friend! Just as moist and flavorful as the chocolate version, vanilla is the star in this cake. Sour cream gives a slight tang in both the cake and the frosting, and also makes it supremely moist. The cake is ridiculously easy to put together, and truly one of my favorite cakes when it comes to texture and crumb. You are going to love it!
Preheat your oven to 350 degrees F. Line a large baking sheet* with parchment paper, or spray well with nonstick spray.
Make the cake batter. In a medium or large saucepan, add 1 cup butter and 1 cup water. Bring to a boil over medium high heat. Once it boils, take it off the heat.
In a medium bowl or stand mixer, combine 2 and 1/4 cups flour, 2 cups sugar, 1/2 teaspoon kosher salt, and 1 teaspoon baking soda. Whisk it together. You can choose at this point to add the dry ingredients to the butter/water in the saucepan and mix it right there, or you can pour the wet ingredients into the bowl of dried ingredients. Both ways work fine.
Stir the wet and dry ingredients together until well mixed, scraping the sides. You can do this by hand or with a mixer.
Add 1 tablespoon vanilla, 1/2 cup sour cream, and 2 eggs. Blend well until all the lumps are gone, making sure to scrape the sides and bottom.
Pour the batter into the prepared pan and spread evenly to the sides.
Bake at 350 for about 18-20 minutes* (check times below), until a toothpick comes out of the center with no wet batter on it. The sides of the cake should just be starting to pull away from the edge of the pan. Don't over bake!
Make the frosting. I like to wait until the cake is out of the oven before starting the frosting. Melt 1 cup of butter. You can do this in a saucepan on the stove, or in a microwaveable bowl.
Add 2 cups of powdered sugar, 1/4 to 1/2 teaspoon kosher salt, 1/2 cup sour cream, and 1 tablespoon vanilla. Use a whisk to beat it together, or you can beat with a hand mixer or in a stand mixer. Mix until there are no lumps.
Add 2 more cups of powdered sugar. Beat well until incorporated. Add the other 1/2 cup of powdered sugar if you like, you can add as much or as little as you want to get your preferred consistency. 4 and 1/2 cups was perfect for me.
If your cake is not done baking when you finish the glaze, stir it every now and then to break up the hardened shell on top.
When the cake is done, take it out of the oven and let cool for 15-20 minutes. Spread the glaze over the cake. Let cool at least an hour before digging in so that the frosting has time to set up. (This is what civiled people do. I'm just not there yet, and usually end up digging into a corner of the hot cake like an animal the moment it's frosted.)
This cake is delicious served on its own! It's also really good served with fresh fruit like raspberries or strawberries.
Notes
*The size of your jelly roll pan is a matter of debate. You can make this cake in a 9x13 inch cake pan (thick cake), a 10x15 inch jelly roll pan (thinnish cake) or an 11x17 inch half baking sheet (thinnest cake). I prefer the 11x17. It gives you the perfect ratio of cake to frosting in my opinion.If you are baking this in a 9x13 bake for 23-25 minutes. If you do a 10x15, bake for about 20 minutes. If you bake it in a 12x18, bake for about 18-20 minutes.All of these times are going to vary because everyone's oven is different!**I love the tang that sour cream adds to the frosting for this cake, and I think you will like it too! But if you are worried it will be too much, use 1/4 cup of sour cream and then add milk to get the consistency of frosting you like.