Preheat the oven to 180℃. Mix the filling ingredients in a bowl until the dry ingredients are well incorporated.
Prepare the crumble topping: Combine all of the ingredients except for the butter, and mix well. Finely cube the butter, add it to the mixture, and mix well.
Layer a pie pan with the frozen pie sheet, pierce with a fork, then pour in the filling. Sprinkle the crumble topping evenly over the top.
Bake for 1 hour in the 180℃ oven.
Story Behind this Recipe
I had a ton of blueberries I bought at Costco, so I decided to make a pie.
You can make the crumble topping easily and quickly if you use a food processor or electric mixer. Otherwise, mixing by hand is fine. To make your own pie crust, see Recipe ID: 1597599. It's very easy and delicious.