Preheat the oven to 350 degrees F. Remove the pie crust from the packaging and set aside. Pour the apple fruit filling into a large bowl and use a knife to coarsely chop the apples in the bowl. Pour all but 1/3 cup of the sweetened condensed milk into the apples, reserve the rest for later. Mix until well blended. Pour into the prepared pie crust and smooth into one even layer.
Melt the butter in the microwave and then let stand at room temperature until cooled, don't add hot butter to the streusel it will make it greasy. In a separate medium bowl, whisk together the flour, brown sugar, cinnamon, apple pie spice, and salt. Add the cooled melted butter and mix until the streusel is evenly combined and forms small clumps. Sprinkle the streusel mixture evenly over the pie. Do not press the streusel into the pie. Use all of the streusel, even if it seems like a lot!
Place the prepared pie on a sheet pan and then bake for 50-60 minutes or until firm and streusel is lightly browned. Remove from the oven and let stand for 1-2 hours at room temperature or until clean slices can be cut.
Drizzle pie with remaining sweetened condensed milk. Cut and serve. Enjoy immediately!