Brooklyn Blackout Cake

Directions

1. 1
   Have ready 2 x 20 cm loose-bottom cake tins at least 5 cm deep.
2. 2
   First make the filling as this requires a cooling time.
3. 3
   Blend the cornflour with about a third of the 600 ml milk until smooth.
4. 4
   Bring the remaining milk to the boil in a small nonstick saucepan with the 300 g sugar, syrup and 100 g cocoa, whisking until smooth.
5. 5
   Add the cornflour solution, bring to the boil, stirring constantly, until you have a rich, thick custard.
6. 6
   Remove from the heat and add the 1 teasp vanilla estract and 100 g butter, stirring until it melts.
7. 7
   Ideally the mixture should be silky smooth but if not give it a quick whiz in a food processor.
8. 8
   Pour into a large bowl, cover the surface with clingfilm, and set aside to cool completely.
9. 9
   Preheat the oven to 190C/Gas 5 and butter the cake tins.
10. 10
    For the cake mixture, cream the 180 g butter and 300 g sugar together in a food processor, then incorporate the eggs one at time, followed by the 1 teasp.
11. 11
    vanilla extract, scraping down the sides of the bowl as necessary.
12. 12
    Sift together the dry ingredients and add them half at a time to the creamed mixture, then add the 200 ml milk with the motor running.
13. 13
    Divide the mixture evenly between the cake tins, weighting them for accuracy and smoothing the surface.
14. 14
    Bake for 30-40 minutes until a skewer inserted at the centre comes out clean.
15. 15
    Run knife around each cake and leave to cool.
16. 16
    Remove the collars from the cakes and slit each one in half horizontally using a bread knife.
17. 17
    Set aside the best-looking top half.
18. 18
    Place the other top half in the food processor and whiz to crumbs.
19. 19
    To assemble the cake, first give the chocolate-custard filling a stir.
20. 20
    Spread a quarter of the filling over one cake base, taking it almost to the rim, place the other bace on top and spread with another quarter of the custard.
21. 21
    Lay the reserved cake top in place.
22. 22
    Coat the top and sides with the remaining custard.
23. 23
    Coat all over the cake crumbs (this is the 'blackout').
24. 24
    When coating the sides, imagion you're making a sand castle, take handfuls of the crumbs and gently press them against the side, leaving any loose ones to fall down and discarding the excess.
25. 25
    Chill for a couple of hours, then cover with clingfilm.
26. 26
    Remove from the fridge 15-30 minutes before eating.