For the base:
1 cup graham cracker crumbs
1 teaspoon instant espresso powder
1 teaspoon cocoa powder
3 tablespoons soft butter*

*see note

For the cake:
500g cream cheese, at room temperature (I used mascarpone)
125g brown sugar
50g white sugar
2 1/2 teaspoons instant espresso powder
2 large eggs
2 large egg yolks
1 tablespoon coffee liqueur (I used mocha truffle flavoured)

For the topping:
50g dark chocolate (I used 62%)
1/3 cup sugar
50g butter
¼ cup strong coffee
1 tbsp coffee liqueur