Chocolate Marshmallow Brownie Cake

A rich chocolate cake topped with gooey marshmallows and homemade chocolate frosting.

This recipe came from a distant cousin who absolutely loved to bake. Whenever family recipes were exchanged, you could always count on her bringing something sweet to the table.

Although the recipe is called a cake, I've always thought it falls somewhere between a cake and a brownie. The chocolate layer is rich and moist, the marshmallows create a gooey middle layer, and the homemade frosting ties everything together.

It's the kind of dessert that disappears quickly at family gatherings, potlucks, and holiday dinners. If you're a chocolate lover, this recipe is hard to resist.

Ingredients: 

Cake:
2 c. flour
1 1/2 c. granulated sugar
1/2 c. light brown sugar
3/4 c. unsweetened cocoa powder
2 tsp. baking powder
1 1/2 tsp. baking soda
3/4 tsp. salt
3/4 c. vegetable oil or melted butter
2 eggs
1 tsp. vanilla extract
6 Tbs. milk
1/3 c. sour cream
1 c. boiling water

For Topping:
10.5 ounce package mini marshmallows

Chocolate Frosting:
1/2 c. butter 
6 Tbs. milk
3 heaping Tbs. unsweetened cocoa powder
1 tsp. vanilla extract
3 c. powdered sugar 

Directions: 

Preheat oven to 350°F. Grease a 9 x 13-inch baking pan.

In a large mixing bowl, whisk together the flour, granulated sugar, brown sugar, cocoa powder, baking powder, baking soda, and salt.

Add the oil, eggs, vanilla, milk, and sour cream. Beat with an electric mixer until combined.

With the mixer on low speed, slowly pour in the boiling water.  Increase speed to high and beat for 1 minute.

Pour the batter into the prepared baking pan.

Bake for 38 to 45 minutes, or until a toothpick inserted in the center comes out clean.  Remove the cake from the oven but leave the oven on. 

Immediately sprinkle the mini marshmallows evenly over the top of the hot cake.

Return the cake to the oven and bake for 3 to 5 minutes, or until the marshmallows are puffed and softened.

Remove from the oven and cool completely.

Make the Frosting
In a small saucepan over medium heat, melt the butter.

Add the milk and cocoa powder. Whisk constantly for 2 to 3 minutes.  Remove from heat.

Stir in the vanilla and powdered sugar, whisking until smooth.

Drizzle or spread the frosting over the cooled marshmallow layer.

Refrigerate for about 30 minutes, or until the frosting is set.

Slice and serve. 

Tips for Best Success:

• Add the boiling water slowly to avoid splashing.
• Frost only after the cake has cooled completely.
• Use fresh marshmallows for the best texture.
• Line the pan with parchment paper for easier serving.
• Let the frosting set before slicing.

Variations and Substitutions:

• Add Pecans or Walnuts:  Sprinkle chopped nuts over the marshmallow layer before frosting.
• Use Dark Cocoa Powder:  For a richer chocolate flavor.
• Try Chocolate Chips:  Add 1 cup to the batter.
• Coffee Boost:  Replace the boiling water with hot coffee.
• Extra Marshmallow Layer:  Use an additional cup of marshmallows for an even thicker topping.

Serving Suggestions:

Serve with:

• A glass of cold milk
• Vanilla ice cream
• Fresh strawberries
• Coffee
• Hot chocolate
• Whipped cream

How to Store:

• Room Temperature:  Store covered for up to 3 days.
• Refrigerator:  Store up to 1 week.
• Freezer:  Freeze individual pieces for up to 2 months.

Frequently Asked Questions:

Is this a cake or a brownie?
It's technically a cake, but many people find the texture somewhere between cake and brownies.

Can I use butter instead of oil?
Yes. Melted butter works well.

Why add boiling water?
It enhances the chocolate flavor and creates a moist texture.

Can I make it ahead?
Yes. It's excellent made a day in advance.

Do the marshmallows melt completely?
No. They soften and create a gooey layer beneath the frosting.