Preheat oven to 325 degrees. Spray 9-inch pie pan with non-stick cooking spray, and place one unbaked pie crust in the pan.

In a medium bowl, mix rhubarb, sugar and cinnamon. Let sit for fifteen minutes, stirring on and off.

Add in the pie filling, apple pie spice and tapioca and mix together.

Pour into pie crust-lined pan, and then lay the second pie crust over the top and flute the edges of the crust.

Bake for 55 minutes and let cool completely prior to serving.