Crush 2 cups of biscuits into fine crumbs
Mix 1 cup milk, 1/2 cup sugar, and 2 tablespoons cocoa powder until smooth
Add 1/2 cup melted butter to the mixture
Combine the biscuit crumbs with the wet mixture
Add chopped nuts or chocolate chips if desired
Grease a cake pan or line it with parchment paper
Pour the mixture into the pan and spread evenly
Refrigerate for 4 to 6 hours until set
Remove from the pan and slice to serve