Homemade Chocolate Liqueur (Bailey’s style)

Homemade Chocolate Liqueur (Bailey’s style)
Ingredients:

200g dark chocolate (at least 70% cocoa), grated or in pieces
400ml sweetened condensed milk
250ml full-fat single cream
300ml whisky (or dark rum if you prefer a sweeter note)
1 tsp vanilla extract
2 tbsp instant coffee dissolved in a little hot water (optional for a stronger taste)
2 tbsp caster sugar (adjust to taste)
Instructions:

Preparation of the chocolate base: