Guinness Black Magic Cake with ermine frosting and whiskey caramel – perfect for St. Patrick’s day!
If you are looking for more Saint Patrick’s Day recipes, why not try my Black Magic Guinness Cocktail?
I have a confession to make. I totally have a thing about Irish accents. My husband is Canadian but his parents are Irish and he unwittingly takes on the accent whenever he is around family (I tease him endlessly, but it does make me slightly weak in the knees).
With St Patrick’s Day tomorrow I thought I would share a recipe that I made last year but didn’t get a chance to photograph or blog.
It is a variation on Black Magic Cake using Guinness instead of coffee. If you have never tried Black Magic Cake you really need to as soon as possible!
It is a very easy cake that is so incredibly moist and chocolatey (though it contains no chocolate, only cocoa powder) that it might as well be brownies!
Paired with ermine frosting and whiskey caramel (use Jameson if you want to keep the Irish theme) it is just pure indulgence.
If you haven’t heard of ermine frosting (also called boiled milk frosting) you aren not alone!
It is an old recipe – and the original filling of red velvet cake – that deserves to be more popular because it is delicious, velvety and so very rich.
The only thing to watch out for is to let the milk roux cool down completely before whisking into the butter otherwise the frosting will flop!
Guinness Black Magic Cake
- 200 g | 7oz plain flour
- 350 g | 12oz caster sugar
- 75 g | 3oz cocoa powder
- 2 tsp bicarbonate of soda
- 1 tsp baking powder
- 1 tsp salt
- 2 large eggs
- 225 ml | 8oz Guinness or you can used black coffee
- 225 ml | 8oz buttermilk or milk soured with 1 tsp lemon juice
- 100 ml | 4fl oz vegetable oil
- 1 tsp vanilla extract
- For the caramel
- 150 g | 2/3 cup caster sugar
- 30 ml | 1/8 cup water
- 100 ml | 3.4 fl oz double cream
- 30 g | 2 tbsp unsalted butter
- 2 tbsp Irish whiskey
- Pinch coarse sea salt
- Ermine frosting
- 200 g | 7oz unsalted butter
- 200 g | 7oz sugar
- 235 ml | 1 cup semi-skimmed milk
- 5 tbsp plain flour
- pinch salt
- seeds from 1 vanilla pod
- Make the caramel. Half fill a frying pan with cold water and keep it handy. Put the double cream and butter in a small measuring jug and microwave for 30 seconds or until the butter melts. Set aside.
- Put the sugar and water in a medium heavy-bottomed pan. Bring to the boil and cook, swirling the pan, until you have a golden caramel – this will take several minutes.
- Remove the caramel from the heat and pour in the cream/butter – be careful, this will cause the caramel to bubble and rise in the pan. Plunge the bottom of the pot in the frying pan to stop the caramel from cooking further. The caramel may seize and curdle – don’t worry!
- Add the salt and whiskey and return the saucepan to the stove and cook the caramel for 2-3 minutes over medium-low heat, whisking continuously until the caramel is smooth.
- Strain the caramel through a fine sieve into a jar and cool in the fridge before using. Caramel will keep in a sterilised jar in the fridge for several weeks.
- Make the frosting. Put the milk and flour in a small saucepan and whisk over medium-low heat until the mixture thickens and the whisk leaves a trail. Transfer to a bowl and cover with cling film, pressing it on the surface to prevent a skin forming. Cool completely before using (speed up the process by putting the bowl in the fridge or freezer).
- Whisk the butter and sugar together for several minutes, stopping the mixer and scraping the sides and bottom of the bowl as you go. Add the vanilla and salt and whisk in.
- Start adding the milk roux, one tablespoon at a time, until the frosting is completely smooth and has the consistency of whipped cream.
- Preheat the oven to 180C (350F). Prepare 3x20cm pans or 2x23cm pans – grease and line the bottoms and sides with baking paper.
- Sift the flour, sugar, cocoa powder, soda, baking powder and salt together into a large bowl.
- Put the eggs, Guinness, buttermilk, oil and vanilla extract into the bowl of your stand mixer and whisk together on low speed until combined.
- Gradually add the dry ingredients and beat for a couple of minutes, scraping the bottom and sides of the bowl. The batter will be fairly thin.
- Pour into the cake tins filling only halfway. Bake the 20cm cake layers for about 20-25 minutes (the 23cm cakes take 30-35 minutes) or until the top of the cake is firm and a skewer inserted in the centre comes out clean. Cool on a wire rack.
- Pipe or spread the frosting over the layers drizzling caramel over each layer before sandwiching together. Pipe frosting over the top layer and drizzle with caramel. Serve at room temperature (the frosting will harden in the fridge).