Follow these easy steps to create your amazing Strawberry Rhubarb Crumble Pie:

1. Preheat Your Oven: Set it to 375°F (190°C).
2. Prepare the Pie Crust: Place the pre-made pie crust into a 9-inch pie pan and gently fit it in. Prick the bottom with a fork to prevent bubbling.
3. Mix the Filling: In a large mixing bowl, combine the sliced strawberries and chopped rhubarb. Add granulated sugar, flour, lemon juice, vanilla extract, and ground cinnamon, mixing until the fruit is evenly coated.
4. Arrange the Filling: Pour the filling mixture into the prepared pie crust, spreading it out evenly.
5. Make the Crumble Topping: In another bowl, combine rolled oats, brown sugar, flour, melted butter, and salt. Mix until the mixture resembles coarse crumbs.
6. Top the Pie: Evenly sprinkle the crumble mixture over the fruit filling, covering it well.
7. Bake the Pie: Place the pie in the oven and bake for 45-50 minutes, or until the topping is golden brown.
8. Check for Doneness: The filling should bubble slightly. If the crust edges begin to brown too quickly, cover them with aluminum foil.
9. Cool the Pie: Once baked, remove the pie from the oven and let it cool on a wire rack for 15-30 minutes before serving. This will help the filling set.
10. Slice and Serve: Enjoy your homemade pie warm or at room temperature with a scoop of ice cream or a dollop of whipped cream.

Once you've completed these steps, you're ready to enjoy a slice of this delicious pie!