Step 1

Grease a 14cm x 21cm loaf pan. Line base and two long sides with baking paper, extending the paper 5cm above edges of pan.

Step 2

Place dark chocolate in a small heatproof bowl over a small saucepan of gently simmering water (don't allow bowl to touch water). Stir until melted.

Step 3

Process ricotta and sugar until smooth; transfer to a medium bowl. Stir in melted chocolate and nougat.

Step 4

Beat cream in a small bowl with an electric mixer until soft peaks form. Fold cream into chocolate mixture. Spoon mixture into pan, cover with foil and freeze overnight.

Step 5

To make chocolate sauce, bring cream almost to the boil in a small saucepan over low-medium heat. Add milk chocolate and stir until smooth.

Step 6

Turn mousse cake onto a serving platter and drizzle with a little of the chocolate sauce. Scatter with raspberries and nuts. Serve sliced with remaining chocolate sauce.