Black Forest trifle

Name: Black Forest trifle
Prep time: 3 h 20 min
Cook time: 14 min
Total time: 3 h 34 min
Cuisine: British, European, German
Ingredients: 2 tbsp cornflour; 2 x 680g jars morello cherries, drained, 1/2 cup (125ml) juice reserved; 1/3 cup (75g) caster sugar; 1/3 cup (80ml) kirsch (see note); 300ml thickened cream; 2 tbsp icing sugar, sifted; 1 chocolate cake (see related recipe), chilled; Grated chocolate, to garnish; 2/3 cup (160ml) milk; 200ml pure (thin) cream; 3 egg yolks; 2 tbsp caster sugar; 2 tbsp cherry jam