Salted caramel and banana trifle with toffee walnuts

Method

1. To make the caramel sauce, stir the butter, sugars and golden syrup in a pan over a low heat for 10-15 minutes until the sugars melt and the mixture is smooth. Stir in the 120ml double cream, 1 tsp vanilla extract and sea salt. Leave to cool.
2.  For the custard, put the milk and 175ml cream into a non-stick pan and bring to the boil. Meanwhile, whisk the egg yolks and caster sugar in a bowl until pale and thick, then whisk in the vanilla bean paste, cornflour and flour. Pour in the hot cream and milk, then whisk. Return the mixture to the cleaned pan and cook over a low heat, stirring, until thick and glossy. Don’t let it boil. Pour into a bowl and press cling film onto the surface. Leave to go cold.
3. Mix the rum and maple syrup in a dish. Briefly dip in each side of the savoiardi biscuits, then layer in the bottom of a 2 litre trifle bowl. Cut the bananas into thin diagonal slices, then scatter on top. Drizzle over 175g of the caramel sauce, spoon over the custard, then cover and chill.
4. For the toffee walnuts, preheat the oven to 200°C/fan180°C/gas 6 and line a baking sheet with baking paper. Toast the nuts on another baking sheet for 8 minutes, then cool. Put the 40g sugar and 90ml water in a small pan over a low heat until the sugar dissolves (don’t stir). Add a pinch of salt, the 1 tbsp butter and ½ tsp vanilla, turn up the heat and boil until thick. Stir in the nuts and cook until coated by the toffee. Quickly tip onto the lined baking sheet and space out with a fork, then cool. (Store in an airtight container if necessary)
5. Shortly before serving, whip the cream (see tips) into soft peaks and spoon on the top of the custard. Drizzle over a little more salted caramel sauce, scatter with the walnuts, then serve with any remaining sauce, if you like.