Preheat oven to 375° Fahrenheit.
Stir apples into sugar, flour, and cinnamon mixture.
Pour into pie shell and sprinkle with water.
For the crumb topping, mix the crumb topping ingredients together in a bowl with a fork until a crumbly mixture is formed. Pour it over the pie.
Bake at 375° Fahrenheit for 60-70 minutes. Check it after 60 minutes and if it doesn't look golden brown enough on the edges, you can leave it in the oven for another 10 minutes.
Let the pie cool down completely on the counter, then cover it and chill in the fridge for at least 1 hour so that it will set. Then slice, serve, and enjoy!