Combine the dry ingredients: Add the dry milk powder, sugar, cocoa powder, and salt to a large bowl. Break up any large clumps before mixing.
Whisk everything together: Slowly whisk the mixture until it becomes completely uniform in color with no streaks of cocoa or pockets of dry milk.
Blend for a smoother texture (optional): Transfer the mixture to a food processor and pulse for 10–15 seconds. This step helps the mix dissolve beautifully in hot liquid.
Transfer to a container: Spoon the mixture into a clean, dry airtight jar or container. Seal tightly and store in a cool, dry cupboard.
To serve: Add 3–4 tablespoons of the mix to a mug. Pour in 1 cup of hot water or warm milk. Stir until creamy and smooth.