Preheat the oven to 350°F. Grease an 8x8-inch baking pan.
In a medium bowl, combine the chopped rhubarb with 1/2 cup of sugar and cornstarch. Stir well and set aside to let the rhubarb release its juices.
In a separate bowl, beat the softened cream cheese with the remaining 1/2 cup of sugar until smooth. Add the sour cream, flour, egg, vanilla extract, almond extract, and salt. Mix until well combined and creamy.
In another bowl, mix the graham cracker crumbs with the melted butter until the crumbs are evenly coated. Press the mixture firmly into the bottom of the prepared baking pan to form the crust.
Spread the cream cheese mixture over the crust evenly. Spoon the rhubarb mixture on top of the cream cheese layer, spreading it out gently.
Bake in the preheated oven for 35-40 minutes, or until the center is set and the edges are lightly golden. Remove from the oven and let cool to room temperature, then refrigerate for at least 2 hours before cutting into squares.
These squares can be served chilled or at room temperature.