• Line an 8-inch (20 cm) square pan with parchment paper, leaving an overhang for easy removal. Set aside.

Make the chocolate biscuit base.

• Place the digestive biscuits (or graham crackers) in a food processor and process until fine crumbs form. Transfer to a large bowl.
  
• In a saucepan, whisk together the sugar and cocoa powder.
  
• Gradually whisk in the water until smooth.
  
• Add the butter.
  
• Bring the mixture to a boil over medium heat and cook for about 5 minutes, stirring constantly, until slightly thickened and glossy.
  
• Remove from heat and let cool for about 5 minutes, then stir in the vanilla extract.
  
• Pour the warm chocolate mixture over the biscuit crumbs.
  
• Mix until evenly combined.
  
• Press the mixture firmly into the prepared pan, forming an even layer.
  
• Set aside.
  

Prepare the coconut cream cheese layer.

• In a bowl, whisk the cream cheese until smooth. Add the powdered sugar, vanilla extract, and salt, and whisk until well combined.
  
• Add the Greek yogurt and mix to combine.
  
• Add the shredded coconut.
  
• Mix until evenly incorporated.
  
• Spread the mixture evenly over the biscuit base.
  
• Smooth the top.
  

Make the chocolate topping.

• Place the chocolate and whipping cream in a heatproof bowl.
  
• Melt gently over a bain-marie (double boiler) on low heat, stirring until smooth.
  
• Pour the melted chocolate evenly over the cream cheese layer and gently tilt the pan to level.
  
• Refrigerate for at least 2–4 hours, or until fully set.
  
• Lift out using the parchment paper, slice into bars with a warm knife, and serve.