I was really into sheet cakes last Fall when I made this Chocolate Blackout Sheet Cake for my first anniversary at work, and then a Rainbow Sprinkle Sheet Cake for my birthday. This S’mores Sheet Cake puts a perfect Summer spin on it, and it was so, so good.

I found the inspiration for this sheet cake on the Family Bites blog, but the original recipe is actually a layer cake from The Smitten Kitchen Cookbook. I love the sheet cake version because it’s just so easy to bake up and bring wherever you’re going* this Summer. It’s a graham cake base, topped with milk chocolate ganache and my favourite marshmallow topping. I didn’t actually use the recipe from the book for the topping just because I’ve discovered over the years that the only one that works for me is this one from A Cozy Kitchen.

I’m finding it’s the little things that are making this Summer feel normal, and making S’mores treats is definitely one of them. Since I won’t be going to Trader Joe’s anytime in the near (or far) future, my next project is going to be making homemade Smashing S’mores!

*I mean, I’m literally going nowhere except my parents’ backyard, which is where I brought this.

S’mores Sheet Cake

Source: recipe from The Smitten Kitchen Cookbook, inspo from Family Bites, marshmallow topping from A Cozy Kitchen.

Ingredients

Graham Cake

• 2 cups flour
• 2 cups graham cracker crumbs
• 2 tsp baking powder
• 3/4 tsp baking soda
• 3/4 tsp salt
• 1 cup (2 sticks) butter, room temperature
• 1 cup brown sugar
• 2/3 cup sugar
• 4 eggs, room temperature
• 2 cups buttermilk

Milk Chocolate Ganache

• 8oz milk chocolate, chopped small
• 3/4 cup whipping cream
• big pinch salt

Marshmallow Frosting

• 2 tbsp water
• 1/2 cup + 2 tbsp sugar
• 2 large egg whites, room temperature
• 1/8 tsp cream of tartar
• 1/8 tsp salt
• 1/4 tsp vanilla

Toppings

• crushed graham crackers
• chopped milk chocolate

Directions

1. For the cake, preheat the oven to 350° and spray a 9×13″ cake pan with non-stick spray.
2. In a medium bowl, whisk together the flour, graham cracker crumbs, baking powder, baking soda and salt.
3. In a large bowl, mix the butter, brown sugar and sugar together until light and fluffy, about 3-5 minutes. Add the eggs one at a time, mixing well after each addition.
4. Alternately add the dry ingredients and buttermilk, beginning and ending with the dry ingredients, mixing after each addition until just combined. Pour the batter into the pan, and bake for 35-40 minutes or until a toothpick inserted into the centre of the cake comes out clean. Let the cake cool completely.
5. For the ganache, add the chocolate, cream and salt to a microwave safe bowl, and heat in 30 second increments, stirring after each one, until chocolate is totally melted and mixture is smooth. Let cool to room temperature. It will thicken to a spreadable consistency after it cools. At that point, use an offset spatula to spread over the cake. It will be a thin layer on a 9×13″ cake, you can double it if you want a really thick layer. Put it in the fridge to firm up.
6. To make the marshmallow topping, set up a double boiler (so, a saucepan with about 2″ of simmering water, with a heatproof bowl set over top that is not touching the water). Add the water, sugar, egg whites, cream of tartar and salt to the bowl. Using an electric mixer, mix together on low speed to combine, then slowly increase speed to high, whipping the mixture to stiff peaks. This should take about 5 minutes. Remove the bowl from the double boiler, and set on the counter on a tea towel. Whip for 2 more minutes, then add the vanilla and mix until combined.
7. Spoon  the marshmallow topping on top of the cake, and spread around making nice swoops with an offset spatula. Using a kitchen torch, toast the marshmallow lightly until golden brown.
8. Sprinkle the crushed graham crackers and milk chocolate chunks over the top.