Hostess Sheet Cake

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Hostess Sheet Cake is a fun homemade twist on the classic lunchbox snack—chocolatey, creamy, and perfect for a nostalgic sweet tooth.

Prep Time50

Cook Time15

Rest Time2 5

Total Time3 10

Course: Dessert

Cuisine: American

Servings: slices

Calories: 662kcal

Author: Jennifer Fishkind

Ingredients

For the Cake:

15.25 ounces 1 Devil’s Food Cake Mix
3 Large Eggs
½ cup Whole Milk
½ cup Coffee
½ cup Vegetable Oil

For the Marshmallow Filling:

2½ cups Powdered Sugar
13 ounces Marshmallow Creme
6 tablespoons Salted Butter room temp
4 tablespoons Heavy Cream
½ tablespoon Clear Vanilla Extract

For the Ganache Topping:

5 ounces Dark Chocolate Chips at least 60% cacao
5 ounces Heavy Cream

For the Vanilla Icing Swirls:

1 cup Powdered Sugar
1½ tablespoons Whole Milk
1 teaspoon Clear Vanilla Extract

Instructions

Preheat the oven to 350 degrees fahrenheit. Line a 12x18 sheet pan with parchment paper, making sure to leave a bit of overhang to remove the cake easily, later on.
In a large mixing bowl, combine all the cake ingredients (cake mix, oil, coffee, milk, and eggs). Mix thoroughly (a hand mixer would make this easiest and quickest).
15.25 ounces 1 Devil’s Food Cake Mix, ½ cup Whole Milk, ½ cup Coffee, ½ cup Vegetable Oil, 3 Large Eggs
Spray the parchment paper on the prepared pan with nonstick cooking spray.
Pour the cake batter in the pan and spread evenly.
Bake for 13 minutes or until a toothpick inserted into the middle comes out clean.
Remove the cake and allow it to cool for about an hour in the pan.
Cut the cake in half, width wise. This should make two cakes that are about 12x9.
Cover the smaller sheet pan with parchment paper and place one of the cake pieces, top down, in the middle of the pan.
In a medium bowl, combine all ingredients for the filling (butter, heavy cream, powdered sugar, marshmallow creme, and vanilla). Mix until no lumps remain (a mixer would also be handy for this step as well).
2½ cups Powdered Sugar, 6 tablespoons Salted Butter, 4 tablespoons Heavy Cream, ½ tablespoon Clear Vanilla Extract, 13 ounces Marshmallow Creme
If the filling is pretty runny or thin, add some powdered sugar until it doesn’t want to immediately flatten and run when added to the cake.
Spoon the filling on to the middle of the cake you placed on the smaller sheet pan and spread it to the edges, evenly.
Take the other half of the cake remaining and gently place it on top of the marshmallow filling, with the top up. Make sure it’s lined up with the other cake half on the bottom. If any filling is pushing out the sides, use a butter knife to gently scrape it away.
Place 5 ounces of heavy cream in a glass measuring cup and heat in the microwave, on high, for 2 minutes and 30 seconds, stopping every 15 seconds to stir so it doesn’t overheat. It’s important to not let the milk boil.
5 ounces Heavy Cream
Place the chocolate chips in a medium mixing bowl and pour the heated heavy cream over the top. Stir until the mixture is smooth.
5 ounces Dark Chocolate Chips
Let the mixture rest for about 5 minutes, or until it starts to thicken a bit, but is still shiny.
Gently pour about half the ganache in the middle of the cake and spread it to the edges. Add more ganache and spread it until the top is fully covered. Allow the cake to rest for an hour, so the ganache can set up.
Once the ganache is set, in a small mixing bowl, combine all the vanilla icing ingredients (vanilla, powdered sugar, and milk) and stir until thoroughly mixed.
1 cup Powdered Sugar, 1 teaspoon Clear Vanilla Extract, 1½ tablespoons Whole Milk
Carefully measure the edge of the cake and make little marks where it will be cut. I do 4x3 to make 12 slices total. You don’t have to do this step, it just makes it easier for the vanilla icing process.
Place the icing in a frosting bag and cut the tip of the bag (not very much, you don’t want too much coming out).
Start in the middle of each slicing row (the marks made earlier) and make a continuous looping line of the icing. Repeat for all rows for a total of 4 looping lines on the cake.
Finally, slice, serve, and enjoy!

Notes

Storage:

Fridge: Store covered for up to 5 days. Let sit 15 minutes before serving.
Room Temp: Fine for a few hours if serving same day.
Freezer: Wrap slices in plastic and freeze in an airtight container up to 2 months. Thaw in fridge, then bring to room temp.

Tips:

Cool cake fully before adding filling.
Line pan with parchment and leave overhang.
Chill assembled cake 30 minutes before slicing.
Use a mixer for smooth, fluffy filling.

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