Add the first 5 ingredients into a blender container and blend until well mixed. Pour into a saucepan and slowly bring to a boil. Turn down and simmer for 10 - 15 minutes, stirring often. When mixture becomes syrupy and coats a spoon remove from heat. Cool slightly and then stir in the vanilla. Refrigerate any unused portions.
When making the individual lattes add 2 - 3 tablespoons of syrup to a coffee mug or glass. Then add about 1/4 cup of half and half, then fill cup with strong coffee and stir.
The amount of syrup, and half and half can be adjusted to meet your individual tastes. Also, you'll need to adjust the proportions accordingly, depending on the size mug or glass being used.