This is one of my FAVORITE cakes of all time. My samoa cookie sheet cake is based off the famous girl scout cookie, and has all the elements of the beloved toasted caramel chocolate drizzled shortbread cookie.

It’s also the final cake of my official sheet cake series I started last month. Better late than never, right? I guess I had a cookbook launch, so we’re all good, right? 😉 Let’s dive right into my samoa cookie sheet cake!

Girl Scout Samoa Cookies into a Sheet Cake

I knew I wanted to include a few of the key elements of the girl scout samoa cookie.

First up – the shortbread crust. I added the shortbread crust to the bottom of the cake underneath the cake batter. No need to pre-bake. Just combine the shortbread crumbles with the melted butter, press it into the sheet cake pan, and you’re all set.

Next, the chocolate caramel cake – I LOVE my chocolate cake. It’s easy, sure-fire, and comes out decadently perfect every time. Make the cake batter in one bowl, and spread it right onto the shortbread cookie crust.

Next up, we have the BEST part – the Toasted Coconut Filling. This takes the cake. It’s gooey, toasted, and filled with caramel flavor. Spread it right on the cake, or add on a layer of caramel buttercream first to act as a barrier. It may be easier to spread it with a barrier, heads up.

I love the ganache drizzle, it looks just like the samoa cookie, doesn’t it? I love that.

Lastly, we have the caramel buttercream. In my new cookbook I think I made it a shortbread caramel buttercream, but for this one it’s just plain caramel, and is still perfection.

How to make a samoa cookie sheet cake

The shortbread cookie crust only needs two ingredients:

  • Shortbread cookies, pulsed to a fine powder
  • Melted unsalted butter

For the chocolate caramel cake, you’ll need:

  • buttermilk – make sure it’s room temperature.
  • sour cream – room temperature again.
  • whole eggs – room temperature.
  • vegetable oil – or you can use melted butter.
  • vanilla – use the good stuff in your buttercream, but you can use imitation in the cake batter
  • caramel extract/emulsion – I find mine online and also at my local baking/craft stores.
  • cocoa powder – I love the Brute dark chocolate cocoa for this recipe, but any other cocoa is fine.
  • chocolate cake mix – I prefer Duncan Hines, but any other chocolate cake mix should be good!

The directions for the cake with shortbread crust are below with the directions. You don’t need your mixer for this recipe – just use a whisk and a bowl and you should be all set. I used a 9×13 cake pan.

How to Make Toasted Coconut Caramel Filling

For the toasted coconut caramel filling, you’ll need a bowl, and then mix these three ingredients together.

  • toasted coconut – you can buy it pre-toasted or toast up your own on the stove in a pan or in the oven on a sheet pan first.
  • sweetened condensed milk – this makes it so gooey and delicious!
  • caramel sauce (either homemade or store-bought) – either way, it’s going to super delicious.

Spread the filling right into the cake, or (like in my video below), you can spread on a thin layer of buttercream first.

How to make caramel buttercream

  • unsalted butter, left out at room temperature for 10 minutes – you need it to be slightly soft, but not softened. If that makes sense, haha
  • salt – just a pinch will do.
  • pure vanilla – use the good stuff!
  • caramel extract/emulsion – I found mine online and also at my local craft/baking store.
  • heavy cream – plus more to thin it out if needed. My go-to is the Darigold one from Costco.
  • powdered sugar – you don’t need to sift it

Combine everything according to the directions below in the instructions. Make sure to let the buttercream whip up really well after everything is incorporated. If you still have air bubbles, which tend to happen, use a wooden spoon to beat them out so that it’s smooth and silky afterwards.

For the herringbone pattern, use a Wilton 1M piping tip and create a shell pulling the tail into the center. Start the next one next to it and pull it into the center again, repeat. There’s a video below with an example of how to do this:

Here’s a quick video of the assembly/decorating process:

If you make my cakes and bakes, I’d love to see it! Make sure to tag me @bakingwithblondie or #bakingwithblondie so I can join in on all the fun.

Happy Baking!

xo, Mandy

Get the Recipe: Samoa Cookie Sheet Cake

Samoa Cookie Cake with a shortbread crust, caramel chocolate cake, toasted coconut caramel filling, ganache drizzle, and caramel buttercream. Just like the girl scout cookie, but better!
Servings: 20 servings, more or less depending on how you slice it
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Ingredients
 

Shortbread Cookie Crust

  • 3 cups shortbread cookie crumbles, pulse the shortbread cookies into a powder and then measure the three cups
  • 5 Tablespoons unsalted butter, melted

Chocolate Caramel Cake

  • 1 cup buttermilk, room temperature
  • 2/3 cup sour cream , room temperature
  • 3 whole eggs, room temperature
  • 1/3 cup vegetable oil
  • 1 Tablespoon vanilla
  • 1 teaspoon caramel extract/emulsion
  • 1/4 cup cocoa powder
  • 1 15.25oz Box Chocolate Cake Mix (I used Dark Chocolate Fudge from Duncan Hines)

Toasted Coconut Caramel Filling

  • 3 cups toasted coconut
  • 14oz can sweetened condensed milk
  • 2/3 cup caramel sauce (either homemade or store-bought)

Caramel Buttercream

  • 1 1/2 cup (or three sticks) unsalted butter, left out at room temperature for 10 minutes
  • 1 pinch salt
  • 1 Tablespoon pure vanilla
  • 1 teaspoon caramel extract/emulsion
  • 1/4 cup heavy cream , plus more to thin it out if needed
  • 7-8 cups powdered sugar

Chocolate Ganache Drizzle

  • 1 cup chocolate melts
  • 1/2 cup heavy cream

Equipment

  • 9×13 sheet pan
  • 1M Piping Tip
  • squeeze bottle
  • angled icing spatula

Instructions
 

For the cake & crust:

  • Preheat the oven to 325 F, and prep a 9×13 sheet pan with a swipe of shortening and dust of flour. Set aside.
  • In a food processor, pulse the cookies into a powder and then measure out 3 cups of cookie powder/crumble. Stir the cookie crumbles with the melted butter until it's evenly distributed. Press firmly and evenly into the bottom of the prepared pan. Set aside, no pre-bake required for the crust.
  • In a large bowl, whisk together all the ingredients except for the cocoa and cake mix. Sift in the cocoa and cake mix, then gently stir to combine (don't overmix). Pour the cake batter onto the crust, then bake for 27-30 minutes until the center is baked through. Let cool completely before decorating.

For the Filling:

  • Stir together all the ingredients in a bowl. Set aside.

For the Buttercream

  • In the bowl of a stand mixer fitted with a paddle attachment, whip up the butter until it's light and fluffy, about 2 minutes. Add in the salt, vanilla, caramel extract, and heavy cream. With the mixer on the lowest speed, slowly start to add in all the powdered sugar, about a half cup at a time. When it's fully incorporated, you may need to add in a Tablespoon or two more of heavy cream if needed to thin out the buttercream. Flip the mixer to the highest speed and whip up the buttercream to lighten the texture for about 2 minutes. Use a wooden spoon to stir and beat out the air bubbles.

For the ganache:

  • Stir together the chocolate and heavy cream in a microwave safe bowl and heat for 30 seconds, stir. Heat 30 seconds again and stir again until smooth. Add to a squeeze bottle and set aside.

Assembly

  • Fill a large piping bag with the caramel buttercream and a 1M tip and set aside (enough buttercream for the entire border – so about 2-3 cups).
  • Spread a layer of buttercream in a flat layer with the angled icing spatula. Carefully spread on the filling, then drizzle on the chocolate in straight lines diagonal. With the reserved buttercream in the piping bag, pipe on a braid pattern around the outside border.