In a small saucepan over medium heat, combine the chopped peaches, water, allulose, brown sugar substitute, and cinnamon. Stir occasionally as the mixture begins to simmer. Let it cook until the peaches soften and the sauce thickens slightly. Set aside to cool.

Step 2: Make the Pecan Crumble

Using a separate small saucepan, toast the pecans over medium heat with butter, sweetener, and salt. Stir often and cook until the pecans are golden and fragrant, about 4-5 minutes. Remove from heat and let the crumble cool completely.

Step 3: Whip the Cheesecake Filling

In a large mixing bowl, whip the softened cream cheese until it becomes light and airy. Add the powdered sweetener and vanilla extract, mixing until fully incorporated. In another bowl, beat the heavy cream until stiff peaks form. Carefully fold the whipped cream into the cream cheese mixture until smooth and uniform.

Step 4: Assemble the Cheesecake Jars

Crumble the pecan mixture into small bits with your fingers. Spoon about 1 tablespoon of pecan crumble into each dessert glass. Pipe or spoon the cheesecake mixture over the pecan layer, filling the jars about 3/4 of the way. Spoon the peach sauce over the cheesecake layer, then top with a sprinkle of leftover pecan crumble. Chill or serve immediately.