Bring the cream to a boil.
In a medium saucepan, bring the water, sugar, and glucose to 180-185°C.
Turn off the heat. While stirring constantly, slowly add the hot cream.
Reheat the caramel to 104-105°C, stirring well.
Transfer to a measuring cup. Add condensed milk and vanilla. Stir.
Allow the caramel to cool to 40-42℃, then add melted gelatin and diced butter—process with hand blender.
Pour into baked tart shells and allow to set.