01 -
Heat your oven to 350 degrees. Spray a 9x13 inch baking pan with cooking spray and set it aside.
02 -
In a large bowl, mix together the flour, rolled oats, brown sugar, chopped pecans, and melted butter with a fork until everything comes together in a crumbly mixture. Scoop out 1 1/2 cups of this mixture and set it aside for the topping later.
03 -
Take the remaining oat mixture and press it firmly and evenly into the bottom of your prepared pan. Pop it in the oven for 10 minutes. When it's done, take it out and let it cool for a few minutes.
04 -
In a medium bowl, beat together the softened cream cheese, sugar, egg, and vanilla until the mixture is smooth and creamy with no lumps.
05 -
Pour the cream cheese mixture over the slightly cooled crust and spread it out evenly with a spatula.
06 -
In a medium saucepan, combine the chopped rhubarb, sugar, cornstarch, and water. Cook over medium heat for 8 to 10 minutes, stirring often, until the rhubarb breaks down and the mixture thickens up.
07 -
If your rhubarb sauce looks too thick to spread easily, stir in a little hot water until it reaches a spreadable consistency. Let it cool down for a few minutes.
08 -
Once the rhubarb filling has cooled a bit, carefully spread it over the cream cheese layer.
09 -
Sprinkle the reserved crumble mixture evenly over the top of the rhubarb layer.
10 -
Bake the bars for 30 to 35 minutes, until the topping is golden brown and the filling is bubbling around the edges.
11 -
Let the bars cool completely at room temperature, then refrigerate them until they're firm and set. This makes them much easier to cut into neat squares.