White Layer Cake with Fudgy Brownie and Decorators Buttercream

filed under: Cakes on February 24, 2016

This showstopping cake could not be easier! Brownie layers perfectly compliment white cake and then are topped with a beautiful buttercream rosette. Cake perfection! Don’t miss my classic American Buttercream Frosting!

Before you go any further I want you to know two things:

  1. I am sharing the semi-homemade version of the recipe here. That is one box of white cake and one box of brownie mix.
  2. You can most definitely make this from scratch! You can use my White Cake Recipe and my favorite From-Scratch Brownie Recipe.

Stunning rosettes cover this flavorful cake... white cake layers complemented with rich fudgey brownie deliciousness!

White Cake with Brownie and Decorator’s Buttercream

Supplies Needed to Make This Cake:

1 box of White Cake

1 box of Brownie Mix

1 Decorator’s Buttercream recipe (below)

8-inch round cake pans

Piping bag with a large star tip (like a 1M or 2D tip)

Stunning rosettes cover this flavorful cake... white cake layers complemented with rich fudgey brownie deliciousness!

To Make this Cake:

Prepare brownie batter. Divide batter between two prepared (the right way!) 8-inch round cake pans. Bake at 350 degrees for 10 minutes, or until the brownie batter is set and starting to crust slightly.

While brownie is baking, prepare white cake according to box or recipe directions.

After 10 minutes in the oven, carefully remove brownies. Equally divide the white cake batter between the two brownie pans and return to the oven to bake for 16-22 minutes. When cake is done it will dome in the center slightly, will have pulled away from the edges of the pan, and will have nicely browned on the sides and top.

Cool completely. (To make frosting the cake easier, place in refrigerator until ready to assemble.)

Stunning rosettes cover this flavorful cake... white cake layers complemented with rich fudgey brownie deliciousness!

How to Frost with Decorator’s Buttercream

In the Decorator’s Buttercream recipe, there is fresh lemon juice. In my opinion, this does NOT give the buttercream a “lemony” flavor, but simply helps to enhance the sweetness. You are welcome to simply use vanilla extract but try it with the fresh lemon at least once.

Try frosting your cake chilled. This rose cake design works best with a crumb coat underneath, but because it has SO MUCH FROSTING, doing a thin crumb coat is best. When you apply the crumb coat to a chilled cake, the crumbs tend to behave a little better. 🙂

I have full tutorials on how to make a Rose Cake here and here.

Stunning rosettes cover this flavorful cake... white cake layers complemented with rich fudgy brownie deliciousness!


The juxtaposition of a light white cake with a thick, dense fudgy brownie layer is not new! I have this cake in my book Surprise-Inside Cakes, and called the Vintage Cake. The recipe was handed down from my grandma and a family favorite!

4.58 from 28 votes
Stunning rosettes cover this flavorful cake... white cake layers complemented with rich fudgy brownie deliciousness!
Decorator's Buttercream
Prep Time
10 mins
Course: Dessert
Cuisine: American
Keyword: buttercream
Author: Amanda Rettke
  • 1 cup (2 sticks or 227g) unsalted butter, room temperature
  • 1/2 cup (115g) shortening
  • 2 teaspoons fresh lemon juice or 1 tsp lemon extract, pure vanilla extract, or almond extract
  • 6 cups (just over a pound) confectioners' sugar
  • 1/4 cup (60g) whole milk*
  • 2 teaspoons meringue powder**
  • 1/2 teaspoon table salt
  1. In a stand mixer with the paddle attachment, cream shortening and butter on medium-high until fully combined and fluffy, about 3 minutes.
  2. With mixer on low speed, add lemon juice (or extracts) and salt.
  3. Slowly add sugar, one cup at a time. Add meringue powder. (The mixture will appear dry.)
  4. Add in milk. Turn the mixer up to medium-high (or high) and beat until light and fluffy (approximately 5 to 8 minutes).
  5. *You may need to add more milk to reach your desired consistency. Start with the 1/4 cup and if the buttercream is still too dry, add in more milk 1 tablespoon at a time until you reach the desired consistency. Make sure the mixer is on low speed when adding in milk and give it at least 30 seconds between each addition.
  6. **You can omit meringue power if you prefer. To achieve the perfect piping consistency, you may need to add more confectioner's sugar.
  8. For extra smooth frosting with less air pockets, add buttercream to a food processor 1/2 batch at a time. Process for 3-5 minutes on high, or until frosting appears smooth and creamy like ice cream.
  9. Place directly into piping bags and seal with a rubber band. Can be stored in piping bag until ready to use, up to 3 months.

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  • Jesia says:

    A little confused by the way the instructions for the cake are written. Initially I thought it called for removing the brownies from the pans and reusing the pans for the white cake. But do you pour the cake batter on top of the par-baked brownies and bake them again?

  • Kathy says:

    Does your homemade brownies mix make enough for this recipe

    • Amanda Rettke says:

      You will want to double that recipe. 🙂

  • Alex says:

    So the brownie bakes apart or together with the white cake? didnt get that part 🙁

  • Wendy Noble says:

    Can you tell me where I can purchase meringe powder?

  • Tracy Irwin says:

    This is the most amazing, fluffiest, and perfectly sweet frosting that I’ve ever made, not to mention, ever tasted! I love it so much! It’s just absolutely delicious and perfect!

  • Brenda says:

    It tried the lemon instead of vanilla and I was amazed.. I think that will be my go to buttercream for now on.

    I love the brownie and white cake, always a hit with everyone.

  • MaryAnn says:

    When you say shortening, do you mean cisco?

    • Elizabeth Keeney says:

      Hi, MaryAnn! I work with iambaker and am happy to help with questions. Yes, we used Crisco. Have a great day!

  • Debbie Savins says:

    Question. Do you leave the brownies in the pan, add the cake mix on top of brownies and continue to bake till cake is done. Or do you remove the brownies, then bake cake and assemble afterwards? Just want to make sure I bake it correctly.

  • Terry Auxier says:


  • Erlinda Padilla says:

    Love too see all your recipes

  • KarenAnne Lasher says:

    Can I use my home made brownies?
    I will need to double the recipe.They are baked in an 8 inch pan so will mine fit in the cake pan?

    Love your recipes!!

  • Claire Chouinard says:

    C’est quoi une 1/2 tasse de raccourcissement?

  • Marina says:

    I did this cake actually 3 of them for high school graduation party absolutely devine, I just frosted regular with some peaks I have to admit it come out beautifully. I got so many compliments on it I gave the credit to you as to where I got the recipe. Thank you so much, and to your great recipes.

  • KayDell Knarr says:

    Your recipes look delicious and I have become a fan just today❣️

  • Jill Brown says:

    I was excited to try this for an early Father’s Day dinner, but ended up extremely disappointed! The baking time is far from accurate and I ended up with a less than acceptable cake. I had to add over 20 minutes of bake time to get the cake part finished and then the brownie was still under cooked! I usually have very little issues baking or just cooking in general, so I will try this again in the future with some moderations to a few of the steps and time.

  • Kimberly Armstrong says:

    I really wanted to love this recipe – so much that I made it a second time after the first was underbaked (white level) even after adding to the recipe’s suggested time. The buttercream suggestion for lemon is a wonderful idea. I don’t like the mouth feel of that much shortening, so I cut the amount in half and substituted butter. It held up well when piping.

  • Lorrie says:

    So what is the answer? Do you put the cake mix on top of the brownie? Several people have asked the question and I don’t see an answer.

    • Elizabeth Keeney says:

      Hi, Lorrie! I work with iambaker and am happy to help with questions. Yes, equally divide the white cake batter between the two pans of brownies (on top of the brownies). Have a great day!

  • Cheri Collier says:

    I have made many Watkins recipes. I cannot think of one that I have been disappointed in. One of many of my families favorites “Chocolate Cherry Cake”. Yum !!! I really need to find your cookbook. Hope you have one, would be proud to have one. Thank you for all the great cooks and recipes !

  • Michelle says:

    I love your Recipes. I only wish mean people would keep their opinion to themselves.

  • Marci kanarick says:

    Always looking for a great frosting recipe. This one looks yummy. How well will it hold up in warmer temps, like those warmer wedding venues?

  • Diane says:

    Where can you buy meringue powder?

  • Annie says:

    Thata so mouth watering cant wait to try bake it

  • Fatiha says:

    Very beautiful cake , I like it, but can you help me to do it, I m from morrocco

  • Vera says:

    I must correct a previous comment….my concerns how this cake would turn out were unfounded….it turned out moist and delicious!! The brownie anc cake layers didn’t settle evenly but it was delicious!! The first I v was perfect and So GOOD too!! I Will make this again! It’s a winner!!!