Step 1

Preheat the oven to 150°C/fan130°C/gas Grease a 22cm diameter springform cake tin.

Step 2

Put the crushed cookies and melted butter in a bowl and mix. Tip into the tin and press down with the back of a spoon. Leave to set in the fridge for 15 minutes.

Step 3

Put the cream cheese, mascarpone, golden caster sugar, cream, vanilla and flour into a large bowl and beat until smooth. Beat in the eggs and egg yolk. Dissolve the instant coffee in 2 tsp hot water, then beat into the mixture with the 2 tsp coffee extract.

Step 4

Spoon the mixture onto the chilled cookie base, then bake for 90 minutes or until set but still with a slight wobble in the centre. Cool completely in the tin, then leave to set in the fridge for at least 2 hours.

Step 5

For the topping, put the butter, crème fraîche and muscovado sugar in a small saucepan and heat gently until melted. Add the chocolate and 1 tsp coffee extract and heat gently for a further 2 minutes, stirring continuously. Remove from the heat, then give it a good whisk. Cool for a few minutes, then pour the topping over the chilled cheesecake. Return it to the fridge to set.

Step 6

Remove the set cheesecake from the tin and dust generously with cocoa powder.