In a medium saucepan, combine the hulled strawberries, sweetener, and water. Bring it to a gentle boil, then lower the heat and simmer for about 20 minutes until the strawberries are soft and the liquid has thickened.
Mash the berries well to remove any large lumps, then let the mixture cool down a bit.
Once the berry mixture is cool, stir in the Greek yogurt, heavy cream, and vanilla extract. Whisk everything until smooth and well combined.
Carefully pour the mixture into your chosen ice cream molds.
If using wooden sticks: Freeze the molds for 2-3 hours first, then insert the sticks before returning them to the freezer.
Freeze for at least 12 hours, or until completely firm.
To easily remove the bars, quickly run the molds under warm water for a few seconds, then gently pull out your frozen treats.