1. Combine the first 2 ingredients and 1 cup sugar in a bowl for a Kitchen Aid Machine fitted with a paddle attachment. Cream until light and fluffy (about 5-6 minutes).
2. Combine the egg yolks and 1/2 cup sugar in a bowl for a Kitchen Aid Machine fitted with a whisk attachment. Whip until the egg yolks double in size.
3. Meanwhile melt the milk chocolate.
4. Combine the heavy cream and the milk powder and whisk until soft peaks gradually adding the ½ cup sugar (set aside).
5. Fold together the kahlua and the whipped egg yolks then fold in the warm melted milk chocolate.
6. Fold together the whipped Plugrá Butter and the egg yolk mixture then fold in the soft whipped cream.
7. Layer evenly between the chocolate biscuit to create 3 layers.
8. Freeze and cut.