Add the sugar, baking soda and salt and blend all the ingredients together well.
Place the hot melted butter into a separate bowl.
Add the cocoa powder and whisk until very smooth.
Add the egg and milk to the chocolate mixture and blend until completely combined.
Pour the chocolate mixture into the flour mixture and stirring from the bottom up mix the ingredients until the flour mixture is just moistened completely.
Place a piece of wax paper on a flat surface and remove the dough to the wax paper.
Form the dough into a rectangle.
Place the dough into the refrigerator and allow it to chill 15 minutes.
Set the oven temperature to 400 degrees and allow the oven to heat while finishing preparing the biscuits.