For your pie crust: Sift half your flour, sugar, and salt into a 9-inch pie plate. In a 1-cup measuring cup, whisk together half your oil and milk and pour over flour mixture. Using a fork, mix until completely dampened. Press dough evenly over bottom of pie plate then up sides and over rim. This will be your bottom crust.
In a separate pan or plate, repeat these steps with the 2nd half of your crust ingredients. I used small star-shaped cookie cutters for decorative top. Cut several stars. Set aside.
For blueberry filling: In a large bowl, stir sugar, cornstarch, and cinnamon. Add blueberries; toss to coat.
Pour filling into your prepared crust. Top with star cut-outs.