Step 1: In a medium heat-proof bowl or saucepan, pour 1 cup of cold water. Sprinkle the unflavored gelatin powder evenly over the surface. Allow it to sit for 5-10 minutes, or until the gelatin has absorbed the water and blossomed into a thick, spongy mass.
Step 2: Bring 1 cup of water to a boil in a separate pot or microwave it until very hot. Pour the hot water over the bloomed gelatin. Whisk continuously until the gelatin is completely dissolved and no granules remain. This should take about 2-3 minutes.
Step 3: Once the gelatin is fully dissolved, stir in your chosen sugar-free flavoring (drink mix powder, syrup, or extract). Stir thoroughly until completely dissolved or well combined. Taste and adjust sweetness/flavor as desired.
Step 4: If adding protein powder, allow the mixture to cool slightly (to lukewarm) before whisking it in. Whisk vigorously until the protein powder is fully integrated and the mixture is smooth. Use a fine-mesh sieve if needed to remove any clumps.
Step 5: Carefully pour the gelatin mixture into individual serving dishes or a large glass dish. Transfer to the refrigerator and chill for at least 4 hours, or until completely set. For best results, chill overnight.