Step 1: In a large bowl, combine the unsweetened cocoa powder, granulated sugar, powdered sugar, and fine sea salt. Add espresso powder now if using.
Step 2: Whisk all ingredients together thoroughly, ensuring there are no lumps and the sugars are evenly distributed. Take your time to get it well combined.
Step 3: (Optional) For an extra smooth mix, sift the entire mixture through a fine-mesh sieve into another bowl. This helps break up any stubborn lumps and ensures a silky texture when prepared.
Step 4: Transfer the finished Easy Homemade Hot Cocoa Mix to an airtight container. A glass jar with a tight lid is ideal for storage and makes for an attractive presentation if giving as a gift. Store in a cool, dry place.
Step 5: To prepare a single serving, scoop 2-3 tablespoons of the mix into a mug. Pour 8 ounces (1 cup) of hot water or hot milk over the mix. Stir vigorously until the mix is completely dissolved and smooth. Garnish as desired with marshmallows, whipped cream, or a sprinkle of cinnamon, and enjoy your instant, delicious hot cocoa!