Stir together sugar, cocoa, and salt in a medium saucepan. Add water, then bring to a light boil for 2-3 minutes, stirring rapidly, until sauce just begins to thicken. Keep stirring so it doesn't burn and also don't let it cook too long or it'll be too thick and more like a hot fudge than a sauce.
Remove from heat, stir in vanilla and optional collagen until dissolved.
If you're using the colostrum, cool the chocolate syrup in the pan on a rack. While it's cooling, use a hand blender or just whisk well the following: 1/4 cup water in pint jar or water glass + heaping Tablespoon of colostrum. Once the chocolate syrup is mostly cooled--when it's no longer hot but still a little warm, then mix the colostrum/water into the syrup. (Cool to about 115* or so if you're usng a thermometer, it takes about 35 minutes, if it's still a bit warm it'll dissolve easiest that way. Even though the colostrum still has health benefits at a higher heat, it's best to keep it raw when possible to preserve the most nutrients.) If you see any lumps, pour it through a fine-mesh strainer into a glass jar to finish cooling, and you could just store it right in that jar.
Or, once totally cool, use a funnel to pour into your container--I reuse a 22 ounce chocolate syrup bottle from the store and it fits perfectly. (It's plastic, which is why I cool it completely first.)
Makes almost 2.5 cups. Use with milk like any chocolate syrup or on ice cream!