Rinse, remove the stems, and slice the strawberries. Blend in a food processor or blender until smooth.

Strain the puree through a fine-mesh strainer into a bowl, pressing down to remove the seeds.

In a medium saucepan over medium heat, combine the strained puree and sugar. Bring to a boil, stirring often.

Reduce the heat and simmer until slightly thickened and the puree coats the back of a spoon. It should be thicker than a sauce but not as thick as jam.

Transfer the puree to a heat-safe container and refrigerate until completely chilled, at least 2 hours.

Chill the bowl and whisk attachment of a stand mixer in the freezer for about 15 minutes.

Add the cold heavy cream and chilled strawberry puree. Mix on medium speed until soft peaks form. Stop the mixer and scrape down the sides and bottom of the bowl.

Continue mixing until stiff peaks form. Add the strawberry extract (or vanilla extract) and salt. Mix just until combined, being careful not to overmix.

Use immediately or store in an airtight container in the refrigerator.