Combine berries and half of the water in a medium sized pot. Bring to a boil over high heat and then reduce heat to medium and cook for 15-20 minutes. Add remaining water, bring to a boil for a couple of minutes, then remove from heat. Strain mixture thru a fine mesh strainer into a clean bowl using a rubber spatula to press as much pulp through the strainer as possible; discard solids. This left me with 3/4 cup dark red raspberry juice.
Rinse out any pulp or seeds that may remain in pot and then add hot strained raspberry juice back in. Add sugar and bring to a boil over medium heat. Reduce heat to low and cook for 5-10 minutes, until slightly thickened. Remove from heat. Stir in vanilla.
Allow syrup to cool from hot to warm, then serve over pancakes. Syrup will thicken as it cools.
Will keep for a week or two if stored in an airtight container in the refrigerator.