Sift dry milk powder, powdered sugar, cocoa powder and salt together in a medium bowl. Add powdered nondairy creamer.
Pour 3½ cups water and vanilla extract into large cast-iron pot (or heavy bottomed stock pot). Slowly add dry ingredients to water, whisking constantly. Pour in chocolate syrup and melted chocolate. Add remaining water to pot and whisk until all ingredients are well blended.
Place on stovetop and cook on low heat for about an hour. Stir well and serve!
Notes
For a grownup twist, consider adding 2 Tbsp of amaretto along with the milk and vanilla!