Whisk together the cream and vanilla until stiff peaks form, then cover and place in the fridge.
In a small saucepan, make the syrup by adding the blackberries, water and tablespoon of sweetener. Cook on a low heat and push down the fruit with a spoon to release the juice. After 10 minutes, press the mixture through a fine sieve, discard the pulp, and let the syrup cool.
Mix together the almond flour and melted butter, then divide evenly between four small bowls or ramekins.
In a stand mixer, beat the cream cheese, blackberry syrup and ¼ cup of sweetener together until smooth. Gently fold in the whipped cream.
Divide the topping between the four bowls, cover, and keep in the fridge until required.
6g net carbs per serving (one individual cheesecake) not including sugar alcohols from the sweetener.