Amish Sour Cream Apple Pie

Preheat the oven to 400 degrees F (200 degrees C).

Beat sour cream and egg together in a mixing bowl. Add white sugar, flour, vanilla extract, and salt. Mix until smooth. Stir in apples. Transfer to the pie crust.

Combine brown sugar, flour, butter, and cinnamon for topping in a bowl. Set aside.

Bake pie in the preheated oven for 25 minutes. Remove from the oven and spread with crumb topping. Return to the oven and continue to bake until golden and bubbly, about 20 minutes more.