Step 1: In a very large bowl, combine the powdered sugar, cocoa powder, dry milk powder, and salt. Ensure the bowl is large enough to allow for thorough mixing.
Step 2: Using a fine-mesh sieve, sift all the ingredients together into another large bowl (or sift in batches). This step is crucial for breaking up any clumps and ensuring a smooth, uniform mix.
Step 3: Once sifted, return all ingredients to the original large bowl if you sifted into a different one. Use a large whisk to thoroughly combine everything. Whisk vigorously for at least 2-3 minutes to ensure all ingredients are perfectly integrated and there are no visible streaks.
Step 4: Transfer the finished Hot Cocoa Mix {Big Batch} into airtight containers. Glass jars or sturdy plastic containers with tight-fitting lids are excellent for storage. Make sure the container is completely dry before adding the mix.
Step 5: Store the Hot Cocoa Mix {Big Batch} in a cool, dark, and dry pantry. When ready to serve, simply add 2-3 tablespoons of the mix to a mug, pour 8-10 ounces of hot water or milk over it, and stir until completely dissolved. Adjust the amount of mix to your taste for sweetness and richness.