Line the base of a 23cm (9-inch) springform tin with baking paper.

Leave a little extra baking paper on the outside of the tin.

In a food processor, combine tea biscuits and 60g of dark chocolate.

Pulse until the mixture forms fine crumbs.

Add cold, cubed butter to the processor.

Pulse until well combined.

Press the mixture into the lined springform tin to cover the bottom evenly.

Refrigerate for 30 minutes.

Remove cream cheese from the refrigerator.

Finely grate the remaining 100g of chocolate (freeze beforehand for easier grating).

In a mixing bowl, whip the thickened cream to form soft peaks.

Set aside the whipped cream.

In another bowl, combine cream cheese, Bailey's Irish Cream Liqueur, and icing sugar.

Whip until well-combined (approximately 3 minutes).

Add the whipped cream and grated chocolate to the cream cheese mixture.

Gently fold in the ingredients.

Pour the mixture onto the refrigerated biscuit base.

Spread evenly with a spatula.

Cover with plastic wrap.

Refrigerate for at least 4 hours, or preferably overnight.

To serve, remove the cheesecake from the tin.

Dust the top with cocoa powder.