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This Oreo chocolate cake is rich, super moist, and topped with sweet Oreo buttercream. Easy to make and perfect for Oreo lovers!
Why You’ll Love This Oreo Chocolate Cake
This cake is gorgeously rich, soft, and chocolatey with the perfect amount of sweetness from the Oreo buttercream.
It’s made with simple ingredients and comes together easily in just one bowl, so there’s minimal fuss and cleanup.
The batter is smooth and light thanks to the warm water and oil, and the result is a beautifully moist cake every time.
If you love anything cookies and cream, especially Oreos, this will become one of your favourite go-to chocolate cake recipes.
What Makes This Oreo Chocolate Cake Recipe Special?
The Oreo buttercream icing is where this cake really shines.
The crushed Oreos give a sweet crunch to the smooth buttercream, which pairs perfectly with the soft chocolate sponge underneath.
It also looks amazing decorated with whole Oreos, making it ideal for celebrations or casual baking days at home.
Equipment You’ll Need For This Oreo Chocolate Cake
- Large mixing bowls
- Electric hand whisk
- 8×8″ (20x20cm) baking tin
- Non-stick baking paper
- Rubber spatula or spoon
- Wire cooling rack
Why This Recipe Works So Well
- Oil and warm water keep the cake moist and soft.
- No mixer required for the sponge – just whisk by hand
- Oreo buttercream adds texture, crunch, and sweetness.
- Great for birthdays, desserts, or a chilled weekend baking session.
Ingredients
For the cake:
- 125g plain flour (1 cup)
- 200g caster sugar (1 cup)
- 65g cocoa powder (¾ cup)
- ¾ tsp baking powder
- ½ tsp bicarbonate of soda (baking soda)
- ½ tsp salt
- 1 large egg, room temperature
- 60ml vegetable oil (¼ cup)
- 125ml milk, room temperature (½ cup)
- 1 tsp vanilla extract
- 125ml warm water (½ cup)
For Oreo buttercream:
- 150g unsalted butter, softened (⅔ cup)
- 200g icing sugar (1⅗ cups)
- 1–2 tbsp milk
- 3 Oreo biscuits, finely crushed
- 9 whole Oreos (optional, for decoration)
Tin size: 8×8” (20x20cm)
Bake time: Approx. 30 minutes at 170C/150C fan (340F/300F fan)
How to Make Oreo Chocolate Cake
Step 1: Whisk the Dry Ingredients
In a large mixing bowl, whisk together the plain flour, caster sugar, cocoa powder, baking powder, bicarbonate of soda, and salt.
This creates an even mixture and distributes the leavening agents evenly through the flour.
Step 2: Add the Wet Ingredients
Add in the egg, vegetable oil, milk, and vanilla extract.
Whisk until the batter is smooth and well-combined, but try not to overmix.
Pour in the warm water and whisk again gently. The batter should now be runny and glossy.
Step 3: Prepare the Tin and Bake
Line your 8×8″ tin with non-stick baking paper.
Pour in the cake batter and give the tin a gentle shake to level it out.
Bake in the centre of the oven for 30 minutes or until a toothpick inserted into the centre comes out with a few moist crumbs.
Allow the cake to cool fully in the tin before decorating.
Oreo Buttercream
Step 4: Whisk the Butter
Add softened butter to a large mixing bowl.
Use an electric whisk to beat it until smooth and creamy.
Step 5: Add the Icing Sugar and Milk
Gradually whisk in the icing sugar and add a tablespoon of milk to loosen the mixture.
Add another tablespoon if needed to make it spreadable, but still thick.
Step 6: Fold in the Crushed Oreos
Use a rubber spatula to fold in the crushed Oreos until fully combined.
You should have a pale grey cookies-and-cream buttercream.
Step 7: Decorate the Cake
Once the cake is fully cooled, transfer it to a serving plate or board.
Scoop the Oreo buttercream on top and spread it out with the back of a spoon or spatula.
Top with 9 whole Oreo biscuits if desired—one for each slice!
Tips for Success
- Make sure your egg and milk are at room temperature so the batter combines properly.
- Warm water helps bloom the cocoa powder and keeps the cake soft and moist.
- Don’t overmix the cake batter once the flour is in— otherwise, it can make the cake dense.
- Wait until the cake is completely cool before adding the icing, or it will melt and fall off.
Storage Tips
Store the finished cake in an airtight container at room temperature for up to 3 days.
Alternatively, refrigerate for up to 5 days and allow it to come to room temperature before serving.
You can also freeze slices of the un-iced cake for up to 2 months.
Watch My Step-by-Step Video
Want to see exactly how I made this Oreo Chocolate Cake?
Watch the full video on the Fitwaffle Kitchen YouTube channel
For more baking videos and fun behind-the-scenes, follow me on:
Instagram – @fitwafflekitchen and @fitwaffle
TikTok – @fitwaffle
Pinterest – fitwaffle
If you loved this recipe, here are two more bakes from www.fitwafflekitchen.com that I think you’ll love:
- Chocolate Fudge Loaf Cake – Moist, rich, and topped with a thick fudge icing.
- Chocolate Fudge Cake Balls – Bite-sized and coated in chocolate. So simple to make!
Both are packed with chocolate flavour and easy to make.
Oreo Chocolate Cake
Ingredients
or the cake:
- 125 g plain flour 1 cup
- 200 g caster sugar 1 cup
- 65 g cocoa powder ¾ cup
- ¾ tsp baking powder
- ½ tsp bicarbonate of soda baking soda
- ½ tsp salt
- 1 large egg room temperature
- 60 ml vegetable oil ¼ cup
- 125 ml milk room temperature (½ cup)
- 1 tsp vanilla extract
- 125 ml warm water ½ cup
For the Oreo buttercream:
- 150 g unsalted butter softened (⅔ cup)
- 200 g icing sugar 1⅗ cups
- 1 –2 tbsp milk
- 3 Oreo biscuits finely crushed
- 9 whole Oreos optional, for decoration
Instructions
How to Make Oreo Chocolate Cake
Step 1: Whisk the Dry Ingredients
- In a large mixing bowl, whisk together the plain flour, caster sugar, cocoa powder, baking powder, bicarbonate of soda, and salt.
- This creates an even mixture and distributes the leavening agents evenly through the flour.
Step 2: Add the Wet Ingredients
- Add in the egg, vegetable oil, milk, and vanilla extract.
- Whisk until the batter is smooth and well-combined, but try not to overmix.
- Pour in the warm water and whisk again gently. The batter should now be runny and glossy.
Step 3: Prepare the Tin and Bake
- Line your 8x8" tin with non-stick baking paper.
- Pour in the cake batter and give the tin a gentle shake to level it out.
- Bake in the centre of the oven for 30 minutes or until a toothpick inserted into the centre comes out with a few moist crumbs.
- Allow the cake to cool fully in the tin before decorating.
How to Make the Oreo Buttercream
Step 4: Whisk the Butter
- Add softened butter to a large mixing bowl.
- Use an electric whisk to beat it until smooth and creamy.
Step 5: Add the Icing Sugar and Milk
- Gradually whisk in the icing sugar and add a tablespoon of milk to loosen the mixture.
- Add another tablespoon if needed to make it spreadable, but still thick.
Step 6: Fold in the Crushed Oreos
- Use a rubber spatula to fold in the crushed Oreos until fully combined.
- You should have a pale grey cookies-and-cream buttercream.
Step 7: Decorate the Cake
- Once the cake is fully cooled, transfer it to a serving plate or board.
- Scoop the Oreo buttercream on top and spread it out with the back of a spoon or spatula.
- Top with 9 whole Oreo biscuits if desired—one for each slice!
Video
