Chocolate Sheet Cake with Warm Chocolate Glaze

This is a soft, moist chocolate cake baked in a single pan and topped with a smooth chocolate glaze. The batter is mixed in one bowl after heating the cocoa mixture on the stove.

🧾 Ingredients

For the Cake

2 cups all-purpose flour
2 cups granulated sugar
½ cup unsalted butter
½ cup vegetable oil
1 cup water
¼ cup unsweetened cocoa powder
2 large eggs
½ cup buttermilk
(or ½ cup milk mixed with 1 teaspoon vinegar)
1 teaspoon baking soda
1 teaspoon vanilla extract

For the Chocolate Glaze

½ cup unsalted butter
¼ cup unsweetened cocoa powder
⅓ cup milk
3 cups powdered sugar
1 teaspoon vanilla extract

🔪 Equipment

13 × 9 inch (33 × 23 cm) baking pan
Medium saucepan
Large mixing bowl
Whisk
Spatula
Measuring cups and spoons

👩‍🍳 Instructions

1️⃣ Prepare the Oven and Pan

Preheat oven to 350°F (175°C).
Grease the baking pan or line with parchment paper.

2️⃣ Heat the Cocoa Mixture

In a medium saucepan, combine:

Butter
Vegetable oil
Water
Cocoa powder

Bring to a gentle boil, stirring occasionally.
Remove from heat immediately once it reaches a boil.

3️⃣ Mix Dry Ingredients

In a large bowl, whisk together:

Flour
Granulated sugar

4️⃣ Combine Hot and Dry Mixtures

Slowly pour the hot cocoa mixture into the flour and sugar.
Whisk until smooth and lump-free.

5️⃣ Finish the Batter

Add:

Eggs
Buttermilk
Baking soda
Vanilla extract

Whisk until fully combined.
The batter will be thin; this is expected.

6️⃣ Bake

Pour batter into prepared pan.
Bake for 20–25 minutes, or until a toothpick inserted in the center comes out clean.

🍫 Make the Glaze

7️⃣ Prepare the Glaze

About 5 minutes before the cake is done:

In a saucepan, combine:
- Butter
- Cocoa powder
- Milk
Bring to a gentle boil, then remove from heat.
Whisk in:
- Powdered sugar
- Vanilla extract
Mix until smooth and pourable.

8️⃣ Glaze the Cake

Pour the warm glaze evenly over the hot cake immediately after removing it from the oven.
Spread gently if needed.

9️⃣ Cool and Serve

Let cake cool in the pan until the glaze sets.
Slice and serve.

🧊 Storage

Store covered at room temperature for 2 days, or refrigerate for 4 days.
Bring to room temperature before serving for best texture.

🍽 Serving Suggestions

Serve plain
Add fresh berries
Serve with whipped cream or vanilla ice cream