It's Girl Scout Cookie season, in case you hadn't noticed. So far it seems to be off to a pretty peaceful start, with no one too mad at the Girl Scout organization over which gluten free cookies they do and don't have for sale. That's a relief. I'm all for Girl Scouts all being able to eat what they sell, but isn't the lesson for them in the selling, not the eating? Either way  I'm fine making my own Girl Scout Cookies. I know there are a few gluten free varieties being sold here and there, but frankly if they're not Samoas or Thin Mints (or at the very least Tagalongs), I'm probably not terribly interested anyway. And since I've already done a whole bunch of GSC copycat recipes here on the blog, and I have modified and perfected recipes for every last one of them in my new (!) cookbooks Gluten Free Classic Snacks, we're moving on to taking the flavors of Girl Scout Cookie favorites and having our way with them. Like in this Samoas-style gluten free chocolate sheet cake. Oh baby…
The Girl Scouts really do know a thing or two about flavor combinations, don't they now. I wonder if we would have thought of the beauty of chocolate-coconut-caramel without them. Now I do not use shredded coconut almost ever, as it doesn't taste like coconut to me. Instead it tastes like sweetened dental floss. There are worse things in this world, but since coconut flakes (sometimes called coconut chips) are far, far superior I see no reason to compromise here. If you can't find coconut flakes (I usually buy them at amazon.com or in my local health food store—Let's Do Organic is a good brand), you can of course use shredded coconut but make it unsweetened if you can. This gorgeous chocolate-caramel cake is plenty sweet already. And rich. And Samoas-like. And just … delicious.
A few notes about size and shape of this cake: As a sheet cake, it's made in a sheet pan. The recipe is developed to be made in a quarter sheet pan (dimensions 9″ x 13″ x 2″). If you don't have a quarter sheet pan (they're sold at Bed Bath & Beyond and they're cheap and super useful!), you can make the whole recipe in an 8-inch square pan at the same temperature, and bake it for a few more minutes. Just keep an eye on things. The icing will not set up quite as well at room temperature since it will be thicker, but it will still set up very well in the refrigerator. And this cake slices best cold anyway.
Happy Girl Scout Cookie season!
Samoas-Style Gluten Free Chocolate Sheet Cake
Ingredients
1 1/4 cups (100 g) unsweetened coconut flakes
For the cake
1 cup (140g) all-purpose gluten-free flour
1/2 teaspoon xanthan gum (omit if your blend already contains it)
3 tablespoons (15g) unsweetened cocoa powder (Dutch-processed works best but natural will work fine)
1 cup (200 g) granulated sugar
1/2 teaspoon baking soda
1/8 teaspoon kosher salt
8 tablespoons (112g) unsalted butter, chopped
1/2 cup (4 fluid ounces) brewed coffee (can replace with an equal amount water)
1/2 cup (112g) sour cream, at room temperature
1 egg (60 g, weighed out of shell) at room temperature, beaten
1/2 teaspoon pure vanilla extract
For the icing
1 3/4 cups (200 g) confectioners’ sugar
1/8 teaspoon kosher salt
1/2 cup (109 g) packed light brown sugar
8 tablespoons (112g) unsalted butter, chopped
1/4 cup (2 fluid ounces)Â milk
1 teaspoon pure vanilla extract
3 ounces semi-sweet chocolate, melted
Instructions
First, toast the coconut. Preheat your oven to 325°F. Place the coconut chips in a single layer on a rimmed baking sheet lined with unbleached parchment paper. Place the baking sheet in the center of the preheated oven and bake until the chips are lightly golden brown all over and smell fragrant (about 5 minutes). Remove the flakes from the oven and allow to cool slightly before crushing the toasted flakes in your hands. Set aside.
Make the cake. Preheat your oven to 325° F. Line a quarter sheet pan (9 x 13 x 2-inches) with unbleached parchment paper and set it aside. In a large bowl, place the flour, xanthan gum, cocoa powder, sugar, baking soda and salt, and whisk to combine well. Set the bowl aside. In a small saucepan, heat the butter and coffee on medium heat, stirring occasionally, until the butter is completely melted. Pour the melted butter and coffee mixture over the dry ingredients, and mix to combine. Add the sour cream, egg and vanilla, and mix to combine. Pour the batter into the prepared sheet pan, and spread into an even layer with a wet spatula. Place the baking sheet into the preheated oven and bake until the cake is uniform and springs back readily when pressed gently with a finger, about 20 minutes.
During the last 5 to 10 minutes of the cake’s baking, make the icing. In a large bowl, place the confectioners’ sugar, salt and brown sugar and whisk to combine well, working out any lumps in the brown sugar. Set the bowl aside. In a clean small saucepan, place the chopped butter and the milk, and cook over medium heat, stirring occasionally, until the butter is completely melted. Remove the saucepan from the stove, add the vanilla and mix to combine. Pour the hot butter and milk mixture over the dry ingredients, and mix to combine.
Ice the cake. As soon as the cake is finished baking, remove the pan from the oven and pour the hot icing over the hot cake. Working quickly to ensure that the icing is spread before it sets, with an offset spatula or butter knife, spread the icing over the entire surface of the cake with an offset spatula or knife. Sprinkle the top of the cake evenly with the crushed toasted coconut chips. Allow the cake to cool to room temperature in the pan. Once the cake is cool, drizzle the top in zig-zag patterns with the melted chocolate. Once the chocolate has set, slice into 8 to 10 pieces, and serve chilled or at room temperature. The cake is easiest to slice with a warm, sharp knife when the cake itself is cold.
Adapted from Chef-In-Training’s recipe for Samoa Sheet Cake and my recipe for Gluten Free Texas Sheet Cake.
KneeKnee says
is the use of parchment paper necessary ?
what is xanthan gum ?
we are new to GF as my daughter was just diagnosed with Celiac. she LOVES samoa GS cookies, and, obviously, can’t have them any longer. she requested this cake for her birthday and I’d like to make it for her.
Donia Robinson says
I think this might be the single most wonderful looking dessert I’ve ever seen (and I’m not prone to hyperbole), based on my mind’s wacky criteria:
1. Not super time consuming
2. The gooey-er the better. Crispy desserts don’t float my boat.
3. Samoa-flavored
I fear that if I make it, I’ll hide it, hoard it, or sit in a closet eating it until it’s gone. But that’s a risk I’m willing to take. Truly, this looks SO amazing. You’ve won. You can shut this all down now. ;)
Cindy says
I made this yesterday for a dinner with good friends. It was my first GF baking experience and it was amazingly wonderful! I purchased your bread cookbook and after having success with this dessert, I am ready to tackle bread!
Anne PW Hawkins says
LOVE that we can print recipes with photos now! Your photography highlights every scrumptious detail, and makes finding favorites easy, visually. Thanks!
Nicole Hunn says
Thanks, Anne! So glad you like that new option (and that you enjoy the photography)!
Jennifer S. says
I’m having a jewelry party next Friday – now I know what to make for the treat!! Yahoo!.
Also, I do not agree that the GS cookie bakers know how to do flavors. Our new one is a nasty oatmeal raisin and our GF is fair at best (toffee chip shortbread).
Nicole Hunn says
I hear you, Jennifer. Nobody bats 1.000 I guess! They really should have just let the whole GF thing go if they weren’t going to do GF versions of everyone’s favorites. :)
Lucy says
Ooooooo, looks amazing Nicole.
We only find the chocolate or vanilla cream sandwich cookies here. I never knew about the other varieties until last year.
So many new GSC to bake :)
Nicole Hunn says
The other varieties are the very best ones, Lucy! You’re in for a “treat” (pardon the pun) to be sure. :)