1. Add raspberries, granulated sugar, lemon juice, and fine salt to a medium saucepan.

2. Cook over medium heat for 4 to 6 minutes, stirring often, until the berries soften and release their juices.

3. Mash some of the raspberries with the back of a spoon while leaving a little texture.

4. In a small bowl, stir cornstarch and water together until smooth.

5. Pour the cornstarch slurry into the simmering raspberry mixture while stirring constantly.

6. Cook for 1 to 2 minutes, until the filling becomes glossy and thick enough to coat a spoon.

7. Remove from heat and stir in vanilla extract.

8. Strain through a fine mesh sieve for a smooth filling, or leave it as is for a textured filling.

9. Transfer to a bowl or jar and chill completely before using in cakes, cupcakes, cheesecakes, or pastries.