The best ever moist chocolate slab cake has a chocolatey rich flavor with a deliciously fudgy buttercream icing that isn't too sweet to go for seconds.
250gramslightly salted buttersoft at room temperature
390gramsicing sugar, siftedapproximately 750 ml or 3 cups
65gramscocoa powderapproximately 185 ml or 3/4 cup
5mlvanilla extractapproximately 1 teaspoon
100grams70% cocoa chocolate, melted and cooledapproximately 1 slab (we use Lindt)
60mlfresh creamapproximately 1/4 cup
Decoration
60gramspecan nutshalves and chopped for sprinkling
Instructions
How to make chocolate slab cake
Heat the oven to 180 degrees Celcius or 160 fan / 350 F / Gas mark 4.
Beat the butter, sugar and eggs together until the sugar is dissolved and the mixture is light and creamy. Scrape down the sides every few minutes to incorporate the batter on the sides and bottom of the bowl. This may take between 7-10 minutes depending on the type of stand mixer you are using.
Add the oil and vanilla extract and beat for another minute.
Mix the instant espresso powder and 125 ml hot water, then and add the milk and stir together.
Stop the mixer and sift in most of the self rising flour, baking powder and cocoa. Mix in the dry ingredients until combined for another 2-3 minutes.
Add the warm espresso coffee mixture and beat until incorporated, for another minute.
Add in the last bit of flour and mix until combined.
Spoon into a greased baking sheet tin (300 x 250 x 50mm) and bake for 25-30 minutes or until a toothpick comes out clean when inserted into the center of the cake. It may require a shorter baking time if you are using a fan assisted oven.
Leave the cake to cool completely before decorating with the chocolate buttercream frosting.
Chocolate buttercream frosting
Beat the butter for 3-5 mins until creamy and light in color.
Add the sifted icing sugar, cocoa powder, salt, vanilla extract and beat until fluffy for at least 1-2 minutes.
Add the cooled melted chocolate and cream and beat again until combined.
Spread the frosting over the cooled cake and decorate with edible flowers or nuts.
Cut into squares and serve with tea or coffee.
Notes
Substitutions:
This recipe can also be used for two 9 inch (23 cm) round sandwich cakes to make a layer cake.
The self rising flour in the recipe can be replaced by 2 1/4 cups cake flour + 2 1/4 teaspoons baking powder. This will take the total baking powder in the recipe to 3 1/4 teaspoons.
I used light brown sugar instead of fine granulated white sugar and the flavor was even better.
The sunflower oil may be replaced with extra virgin olive oil.
The fresh cream in the frosting may be replaced by Nestle Dessert cream.