Black Tahini Chocolate Sheet Cake
This black tahini chocolate sheet cake is moist, tender & full of flavour. Finished with a rich, chocolate fudge frosting, this one's hard to beat!
Servings: 15 Portions
Equipment
- 9" x 13" Baking Tin (See Notes)
- Stand Mixer
- Mixing Bowls
- Sieve
- Palette Knife
Ingredients
Chocolate Sheet Cake
- 1 tbsp Instant Coffee Granules
- 85 g Dutch Processed Cocoa Powder See Notes
- 200 g Boiling Water
- 275 g Plain Flour
- 1¼ tsp Baking Powder
- 2½ tsp Bicarbonate Of Soda
- 1 tsp Table Salt
- 275 g Caster Sugar
- 150 g Light Brown Sugar
- 280 g Buttermilk At Room Temperature
- 100 g Black Tahini
- 50 g Vegetable Oil
- 3 Large Eggs At Room Temperature
- 1 Egg Yolk
Chocolate Fudge Frosting
- 120 g Dark Chocolate 72% Is Best!
- 50 g Dutch Processed Cocoa
- 100 g Boiling Water
- 200 g Unsalted Butter Softened
- A Pinch Of Sea Salt
- 250 g Icing Sugar
- 2 tbsp Golden Syrup
Instructions
Chocolate Sheet Cake
- Preheat an oven to 180°c/160°c fan (356°f/320°f).
- Line a 9" x 13" baking tin with baking parchment then set aside.
- Place the coffee granules & cocoa powder into a small mixing bowl then pour over the boiling water. Whisk until smooth then leave to bloom & cool slightly.
- Next, sift the flour, baking powder & bicarbonate of soda into a large mixing bowl then add in the salt & both sugars. Whisk to combine.
- To the dry ingredients, add the buttermilk, tahini, oil, eggs, yolk & the cocoa & water mix. Whisk until combined & smooth then immediately pour into the lined baking tin.The bicarb will start to react as soon as the batter is mixed, so it's important to get it into the oven as soon as possible!
- Bake the cake for 35-40 minutes, until a skewer inserted into the centre comes out clean then leave to cool completely, in the tin. This will take a couple of hours.
Chocolate Fudge Frosting
- Roughly chop up the dark chocolate then place into a small, heatproof bowl. Melt the chocolate (either in a microwave or over a bain marie) then leave to cool completely.
- Next, place the cocoa powder & boiling water into another small mixing bowl & whisk to combine. Leave this to cool completely as well.
- Once your chocolate is cool, it's time to make the frosting. To do this, place the softened butter & pinch of sea salt into the bowl of a stand mixer then mix with the paddle attachment for 2 minutes, to combine.
- Sift the icing sugar into the butter then continue mixing on a medium speed, until pale & fluffy. This will take 4-5 minutes. Make sure to scrape down the mixing bowl regularly, with a spatula.
- Add the golden syrup, the cooled down melted chocolate & the cocoa mix into the butter then continue mixing for 2-3 minutes, until well combined.
- Scrape down the bowl & paddle with a spatula then give the frosting one brief, final mix.
Assembly
- Spoon the frosting over the top of the cake then use a palette knife to spread out to each corner, creating swirls in the frosting as you do so.
- Let the cake chill in the fridge for 15 minutes, to firm up the frosting slightly then cut into portions & serve.
Notes
1. Cooking In An Aga - Bake the sheet cake on a grid shelf placed on the floor of the baking oven.
2. Storage - This cake is best eaten on the day that it was made. However, if kept covered at room temperature, this cake will keep for several days. Alternatively, for a few days extra shelf life, keep the cake in the fridge then bring back up to room temperature before serving.
3. Baking Tin - The baking tin that I use, is a Nordic Ware 9" x 13" baking tin. Any brand will work but make sure to use a tin that's roughly 2.5" deep.
4. Cocoa Powder - For the best flavour & colour, make sure to use Dutch processed cocoa powder in both the cake & frosting. This is available to buy in most supermarkets. If you're in the UK, I'd recommend Green & Black's.
5. Tahini - Feel free to use white tahini instead of black, if you'd prefer but keep in mind that the cake won't be quite as dark. To make the cake without tahini, use 100 grams of veg oil instead.
6. Room Temperature Ingredients - Before making the cake batter, make sure that the buttermilk, tahini & eggs are all at room temperature. This is key to making a smooth, well combined batter. For the frosting, make sure that the butter is well softened & that the chocolate/cocoa are cool.