A sweet cinnamon spiced cake, topped with a rich dark chocolate ganache, and finished with a homemade marshmallow fluff! This S'more Sheet Cake is the ultimate summertime baking treat.
In a large bowl, whisk together flour, sugar, baking powder, salt, and cinnamon. Set aside.
Beat eggs, milk, and vanilla together.
Add wet ingredients to dry ingredients.
Whisk to combine.
Stir in melted butter.
Pour into prepared pan and bake for about 25 minutes, until cake tests done.
Ganache:
Place chocolate in a medium heatproof bowl. Set aside.
Heat cream on stove until it bubbles around the edges.
Pour over chocolate.
Let stand for 15 minutes.
Gently stir until completely combined and smooth.
Cover ganache with a piece of plastic wrap touching the chocolate to prevent skimming.
Place in refrigerator for 20-30 minutes, until it thickens.
Marshmallow Topping:
Combine gelatin and 1/4 cup water in the bowl of a stand mixer.
In a saucepan, combine remaining 1/4 cup water, sugar, salt, and corn syrup.
Cook over medium heat until sugar dissolves, stirring constantly.
Once sugar is dissolved, stop stirring.
Brush the sides of the pan down with a pastry brush dipped in warm water.
Allow to cook, without stirring, to 240 degrees on a candy thermometer.
Remove from heat.
With mixer running at low speed, slowly pour in syrup.
Continue beating for 5 - 10 minutes, until thickened but still soft.
How To Assemble:
Spread chocolate ganache on top of cooled cake.
Let sit for about 5 minutes, until firm.
Spread marshmallow topping on cake.
Using a kitchen torch, toast the marshmallow topping.
Notes
You can make the cake ahead of time but not the ganache or marshmallow fluff.
The marshmallow fluff will become harder to cut through as it cools. I fixed this by hitting it with a blow torch for a few seconds to warm it back up.
The ganache will melt slightly.
You can store this cake in the fridge.
Make sure not to over mix the cake batter!
A thermometer is needed to make the marshmallow fluff. You may burn it or create candy if you cook it anymore than the recommended temperature.
You can make the ganache over a bain-marie (double boiler).