Preheat your oven to 350°F (175°C) and prepare your baking pan with butter or non-stick spray.

In a large bowl, combine flour and sugar, then cut in the butter until coarse crumbs form. Press into the pan and bake for 10 minutes.

Blend together sugar and flour separately, whisk in cream and eggs, and fold in chopped rhubarb.

Pour the custard filling over the baked crust and bake for an additional 40-45 minutes until set but still slightly jiggly.

Allow the bars to cool at room temperature completely.

Beat cream cheese, sugar, and vanilla until smooth, then fold in whipped cream and spread over cooled bars.

Refrigerate for at least 2 hours before serving. Cut into squares or rectangles and enjoy.