Crush the crackers. Place graham crackers in a zip-top bag and crush with a rolling pin until fine, or pulse in a food processor.
You want sandy crumbs with a few small bits for texture.
Make the crust. In a bowl, combine crumbs with a pinch of salt and 2 tablespoons melted butter or oil. Stir until the mixture looks like damp sand and holds when pressed. If it’s too dry, add up to 1 more tablespoon of fat.
Pack the base. Spoon 1–2 tablespoons of crust into each jar.
Press down with the back of a spoon or your fingers to form a firm layer. Set aside.
Beat the cream cheese. In a mixing bowl, beat softened reduced-fat cream cheese until smooth and fluffy, about 1–2 minutes. Scrape the bowl as needed to avoid lumps.
Sweeten and flavor. Add your sweetener, vanilla, lemon juice, and optional zest.
Beat again until combined and silky. Taste and adjust sweetness or lemon to your preference.
Fold in yogurt. Mix in Greek yogurt on low speed or with a spatula until the filling is smooth and airy. If using, gently fold in whipped topping last for extra lightness.
Fill the jars. Spoon or pipe the cheesecake mixture over the crusts, dividing evenly.
Smooth the tops with the back of a spoon.
Chill to set. Cover and refrigerate for at least 2 hours, or up to overnight. This helps the texture firm up and flavors meld.
Add toppings. Right before serving, add berries, a thin swipe of fruit compote, or a sprinkle of crumbs for crunch. Keep toppings light to stay low-calorie.
Serve and enjoy. Eat straight from the jar.
Keep extras in the fridge for a quick, portion-controlled treat.