Chop the strawberries and add them to a medium sauce pot.

Heat the pot over medium heat.

Add the sugar, vanilla extract, and lemon juice to the pot. Stir to combine.

Cover the pot and let it cook for about 15 minutes, stirring often.

Once the strawberries have softened, use an immersion blender to puree the mixture. Alternatively, use a regular blender or food processor.

If using for frosting or cream filling, strain the puree to remove chunks.

To thicken the sauce, mix cornstarch with cold water and whisk into the sauce until thickened.

Remove the pot from heat and let the sauce cool to room temperature.

Transfer the cooled sauce to an airtight container and store in the refrigerator for up to 7 days.

For longer storage, freeze the sauce in an ice cube tray for easy portioning.