The most delicious peach biscoff sheet cake is here! With peach filling made with fresh peaches, creamy biscoff buttercream, and biscoff cake baked right onto a biscoff crust, this cake is the perfect transition cake from summer to autumn! And since so many of you have asked for more sheet cakes, we’re back again with a few new fall sheet cakes this next month. I can’t wait to share them with you.

Fall Cakes are Here!

The air has been a bit cooler around here and the leaves are beginning to change here and there. That means that fall cakes are all on the way. Until then, I’ve shared a TON of fall-inspired cakes on my landing homepage, so make sure to check those out.

Biscoff Three Ways

For this cake, we have a biscoff (you know, those cookies from the airplane if you fly Delta?) crust, Biscoff spread, and a tender biscoff cake. I wanted the Biscoff to be the star, and then use lots of my delicious peach filling to help, too. So you get both! Two delicious flavors have come together for such a mouthwatering cake.

How to make the best peach filling for cakes

I LOVE this filling. I’ve made it plenty of times and really enjoy how quickly and easily it comes together without sacrificing any flavor.

Fresh peaches are delightful fruits that are loved by many. Their vibrant colors, juicy flesh, and sweet aroma make them a perfect summer treat. Whether enjoyed on their own, sliced into salads, or used in various recipes, peaches never fail to bring a burst of freshness to any cake!

When selecting peaches, look for ones that are firm but slightly soft to the touch. Their skin should have a velvety texture and be free from any blemishes or bruises. To enjoy the full flavor of a peach, allow it to ripen at room temperature until it reaches the desired level of sweetness.

Here’s what you’ll need:

  • fresh peaches
  • brown sugar
  • lemon juice
  • cinnamon
  • nutmeg
  • water
  • cornstarch

Combine everything together except for the water and cornstarch over medium heat. When it starts to bubble and the peaches are softening, add in the slurry (water and cornstarch mixed together in a small bowl). It will thicken, then stir until it bubbles a bit more, then it’s all ready! Let it cool in the fridge until you’re ready to use it on the cake.

How to make a Biscoff Cake & Biscoff Crust

You’re going to start with the cake mix base and doctor it up to make it taste PERFECT! For the crust, you only need two ingredients and you won’t need to pre-bake it, either. Super easy!

  • biscoff cookies
  • unsalted butter
  • buttermilk
  • sour cream
  • eggs
  • vegetable oil
  • vanilla
  • biscoff spread
  • white cake mix

The directions for the biscoff cake and biscoff crust are below with the instructions.

How to make biscoff buttercream

Biscoff buttercream is truly divine! With its rich and creamy texture, coupled with the irresistibly sweet and spiced flavors of Biscoff, this buttercream takes any dessert to a whole new level of deliciousness.

What makes Biscoff buttercream so exceptional is the blend of ingredients that make up its sensational taste. A generous amount of Biscoff spread, made from speculoos cookies, is combined with creamy butter and a hint of vanilla extract. This magical combination creates a velvety, buttery frosting that is impossible to resist.

Whether you’re planning a special occasion or simply craving a sweet treat, Biscoff buttercream can be the star of the show. It pairs perfectly with a wide range of desserts, from cupcakes and cookies to brownies and pies. The versatility of this delectable frosting allows you to unleash your creativity in the kitchen and create mouthwatering desserts that will impress family and friends.

Here’s what you’ll need:

  • unsalted butter
  • biscoff spread
  • salt
  • vanilla
  • heavy cream
  • powdered sugar

Make sure to let your butter whip up until it’s light and fluffy before adding in the other ingredients. This will help it combine better and will improve the overall texture. Also, at the end, get those air bubbles out by using a wooden spoon or spatula to create a creamy texture – perfect for piping these beautiful designs.

How to assemble the biscoff peach sheet cake

This is the coolest thing about these sheet cakes – YOU can decorate or assemble them any way you’d like to! No stacking or clean edges needed – just flavors, design, and texture coming together. That said, here’s how I decorated my sheet cake:

  1. Start by spreading on a layer of buttercream. I used a cake scraper with a scallop design for the base.
  2. Next, I used a Wilton 125 piping tip to make the herringbone design in lines across the cake. I went in one direction, then came back in a different direction.
  3. I then added on a bit of the crumbled biscoff cookies in a line right next to the piped buttercream pattern.
  4. Lastly, I added on some heaping rows of the peach filling. I honestly had forgotten to add it (ugh) or I would have maybe spread it all across the entire cake. It’s so yummy! I served the slices with another dollop of the filling so everyone could still get plenty of it.

That’s it! I love how cozy and fall-ish this cake turned out looking and tasting!

That first slice can be kind of a doozy to get out of the pan, so don’t even worry about it looking perfect! After that, it’s smooth sailing with a sharp knife and proper lifting spatula.

Here’s a video of the peach filling process:

Here’s a video of the sheet cake making & decorating process:

I can’t wait to see what you create/bake! Make sure to tag me so I can join in on all the fun on social media @bakingwithblondie #bakingwithblondie.

As always, happy baking!

xo, Mandy

Get the Recipe: Delicious Peach Biscoff Sheet Cake

The most delicious biscoff sheet cake with a biscoff crust, biscoff buttercream and peach filling – it's perfect for end of summer and beginning of fall!
Servings: 12 servings
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Ingredients
 

Biscoff Sheet Cake with Biscoff Cookie Crust

  • 48 biscoff cookies , pulsed into a fine powder
  • 1/2 cup unsalted butter , melted
  • 3 whole large eggs , room temperature
  • 3/4 cup buttermilk, room temperature
  • 1/3 cup sour cream , room temperature
  • 1/2 cup biscoff spread
  • 1/3 cup vegetable oil
  • 1 Tablespoon vanilla
  • 1 Box White Cake Mix (15.25oz)

Peach Filling

  • 4 Large ripe peaches (about 4 cups), chopped into fine small pieces
  • 1 Tablespoon lemon juice
  • 1/2 cup brown sugar
  • 1 teaspoon cinnamon
  • 1/2 teaspoon nutmeg
  • 1/4 Tablespoon water
  • 1 teaspoon cornstarch

Biscoff Buttercream

  • 3 sticks (or 1 1/2 cup) unsalted butter
  • 1 pinch salt
  • 1 Teaspoon vanilla
  • 3/4 cup biscoff spread
  • 1/4 cup heavy cream
  • 8 cups powdered sugar

Garnish

  • 2 cups crumbled biscoff cookies

Instructions
 

For the Biscoff Cake with Biscoff Cookie Crust

  • In a food processor, mix together the cookies & melted butter until a crust forms. Press the crust into a 9×13 pan firmly in an even layer. Set aside. No pre-bake required. Preheat oven to 325 degrees.
  • In a large bowl, hand whisk together all the ingredients except for the cake mix until thoroughly combined. Sift in the cake mix, and fold it into the other ingredients (don't overmix). Spread cake batter onto the prepared crust. Bake for 35-37 minutes (this is a good time to make the peach filling). Remove from oven and let cool completely before adding on buttercream.

For the Peach Filling:

  • Stir all the ingredients together in a saucepan (except for the water + cornstarch mixed together (slurry)). Heat over medium high heat until the peaches have softened, then add in the slurry (water & cornstarch mixture). Let bubble and thicken, then store the peach filling in a container in the fridge until it's cooled completely.

For the Biscoff Buttercream

  • In the bowl of a stand mixer fitted with a paddle attachment, whip up the butter until it's light and fluffy. Then add in the salt, vanilla, biscoff spread, and heavy cream. Mix again on medium speed until it's all combined. Slowly add in the powdered sugar. Whip up on high speed for 2 minutes, then add in a tablespoon more heavy cream if needed to thin out the buttercream. If it's too thin, add more powdered sugar to control the consistency. Use a spatula or wooden spoon to hand beat out any air bubbles for a more smooth consistency.

Assembly

  • There are more than one way to assemble the cake, so it's totally up to you. For my cake here, I spread a layer of buttercream over the entire cake, then used a scalloped cake scraper to make the bumped texture. Then I used a Wilton 125 piping tip to pipe the herringbone lines across the cake, and then added on the crumbled biscoff cookies and peach filling on top. Enjoy!
Author: Mandy Merriman – Baking with Blondie