In a medium saucepan over medium heat, combine the chopped rhubarb and 1/4 cup of granulated sugar. Cook for about 5-7 minutes, stirring occasionally, until the rhubarb is soft and has released its juices. Remove from heat and stir in the vanilla extract. Let it cool completely.

In a large mixing bowl, beat the softened cream cheese with an electric mixer until smooth. Add the sour cream, powdered sugar, lemon juice, and lemon zest. Mix until well combined and creamy.

In a separate bowl, whip the heavy cream until stiff peaks form. Gently fold the whipped cream into the cream cheese mixture until fully incorporated.

If using gelatin, dissolve it in 1 tablespoon of warm water and stir it into the cream cheese mixture for added stability.

In serving glasses or bowls, layer the rhubarb mixture and the cheesecake cream. Start with a layer of rhubarb, followed by a layer of cheesecake cream, and repeat until the glasses are filled. Top with graham cracker crumbs.

Chill the desserts in the refrigerator for at least 2 hours before serving to allow the flavors to meld.