In a large mixing bowl, whip the heavy cream until it reaches soft peaks. Transfer the whipped cream to another bowl and refrigerate.
Place the cream cheese in the bowl and beat until soft, then add the allulose and beat until well-mixed.
Add the Keto Chow and vanilla extract to the cream cheese mixture and beat well until all the Keto Chow is incorporated.
Stir in half of the chilled whipped cream and mix well to combine and lighten the mixture.
Add the other half of the whipped cream and fold it in gently to retain the air in the mixture.
Spread the cheesecake into the tart pan and chill until set.
When cheesecake has set, arrange raspberries and blueberries on the top.
Just before serving, whip the remaining half of the heavy cream with the powdered sweetener until it reaches stiff peaks. Decorate the cheesecake with the whipped cream and serve.
Store any leftover cheesecake tightly sealed in the refrigerator for up to three days.