Melt chocolate chips, cocoa powder, butter, condensed milk & sugar in a pan on medium-low heat.

Keep stirring the chocolate mixture on medium-low heat until fully melted and well combined. Remove from heat.

Stir in eggs and whisk with a wire whisk until the eggs are well incorporated into the chocolate mixture.

Return the pan to the heat and continue stirring with the wire whisk on medium-low heat until the chocolate custard mixture thickens and forms a paste

Mix in the biscuits,chopped walnuts into the chocolate custard mixture and stir with large metal spoon until the biscuits and walnuts are well coated

Pour the mixture into a rectangular cake tin and press the mixture using hand.

Chill in the refrigerator for at least 1 hour or overnight to set. Once set, cut into squares and serve with your favorite drinks.