Blueberry Layer: (or one 21oz can blueberry pie filling)
3cups(420g)frozen blueberries
½cup(100g)sugar
¼cup(40g)cornstarch
Instructions
Prepare Streusel: Put oats, sugar, flour and cinnamon in a bowl. Add butter and mix together with a fork until pea size crumbs form. Set aside.
Prepare Cheesecake: Place cream cheese, sugar, and flour in a bowl. Cream together with a hand mixer for 1 minute or until smooth. Scrape bowl. Add egg and vanilla. Mix until incorporated. Set aside.
Prepare Pie Crust: In a large bowl, combine flour and salt. Cut in the shortening with a pastry blender or fork until pea size crumbs form. Whisk egg and add to flour mixture. Add COLD water and white vinegar. Mix together with hands and form into a ball. Lightly dust working surface with flour. Roll out pie dough into a circle about ¼-inch thick. Place crust into a deep 9-inch pie dish. Cut off excess dough with a knife against the edge of the pie dish. Discard excess. Crimp pie edges.
Spread cream cheese mixture on the bottom of the prepared pie crust. (Place in fridge or freezer, if needed, to keep the crust cold, while you prepare the next step.)
For the Blueberries: Place frozen berries in a large bowl. Toss with sugar and cornstarch, then gently spoon the blueberries over the cheesecake layer, distributing the cornstarch-sugar mixture as evenly as possible. OPTIONAL: Microwave blueberries to dissolve some of the cornstarch-sugar. Heat in microwave for 60 seconds. Stir. Repeat 3 times making sure to gently fold the berries as they thaw slightly. (The berries won't be completely thawed, but starting to release juices and soften.) Gently spoon evenly over the cheesecake layer.
Sprinkle the prepared streusel over the blueberry layer.
Bake at 350 degrees Fahrenheit for 1 hour and 15 minutes or until the blueberry filling bubbles in the center and the crust and streusel is browned. If browning occurs before filling bubbles, cover pie with foil. (Check at the 1 hour mark.) Consider placing a pan to catch any spills on the oven rack below the pie, especially if you are not using a deep pie dish. Allow pie to cool to room temperature. Cover with plastic wrap and store in the refrigerator.
Notes
*Substitute canned blueberry pie filling for the frozen fruit mixture if desired. Bake time may lessen. Check pie after 1 hour. *I highly recommend using a clear pie dish to be able to see if the crust is fully cooked and browned on the bottom.