Preheat oven to 450F.

Mix streusel ingredients together with a fork or pastry cutter until crumbly and set aside.

Place pie crust in a deep dish pie plate and flute edges.

Whisk together ingredients for pie filling and pour into crust.

Bake at 450F for 15 minutes, then remove pie from oven.

Reduce oven temperature to 350F.

Gently sprinkle streusel over the top of the pie and return to the oven.

Bake 40-45 minutes more or until a knife inserted comes out without wet batter clinging to it.

Cool pie completely and serve.

Refrigerate unused portions.