- 250g pack softened butter, plus extra for the tins
- 100ml strong black coffee (made with 2 tbsp coffee granules), cooled
- 280g self-raising flour
- 250g golden caster sugar
- ½ tsp baking powder
- 4 eggs
- 1 tsp vanilla extract
- 85g walnut, 2 tbsp roughly chopped, the rest finely chopped
- 1 tbsp icing sugar
- 140g mascarpone
- 100g quark
- 140g fondant icing sugar
- Heat oven to 180C/160C fan/gas 4.
- Oil and bottom-line a 20cm round (6cm deep) loose-bottom tin.
For the cake:
- Mix the coffee with 2 tsp warm water and set aside.
- Tip the flour into a large mixing bowl.
- Stir in the baking powder, ground almonds, both sugars (use fingers to rub out any lumps from the muscovado) and walnuts, then make a dip in the centre.
- Put the eggs, yogurt, oil and coffee mix into the dip and stir the mixture with a wooden spoon so everything is evenly mixed.
- Spoon the mixture into the tin, smooth the top to level it, then bake for 40-45 mins, or until a skewer inserted into the centre of the cake comes out clean.
- Let the cake cool in the tin briefly, then turn it out and peel off the lining paper.
- Leave to cool completely while you make the filling and icing.
Make the syrup for the filling:
- Put the caster sugar and coffee into a small, heavy-based saucepan, then pour in 3 tbsp water.
- Heat gently, stirring to help the sugar dissolve.
- Once dissolved, raise the heat, then boil at a fast rolling boil for about 2½-3 mins until thickened and syrupy.
- Pour into a small heatproof bowl and set aside to cool.
- When cold it should be the consistency of treacle.
For the filling and icing:
- Beat the mascarpone, quark, icing sugar and vanilla together until smooth, then stir in the cold coffee syrup. Set aside.
- For the icing, sift the fondant icing sugar into a bowl.
- Mix the coffee with 1 tbsp warm water, stir this into the fondant icing sugar with about 1 more tsp water to give a smooth, thick but spreadable icing.
- Split the cake into 3, then sandwich back together with the filling.
- Spread the icing over the top, scatter over the chopped walnuts and leave to set.
Store in the fridge.