Crust:
In a medium bowl, whisk together the flour, salt and sugar.
With the large holes of a box grater, grate the butter into the dry ingredients.
With a fork, toss the butter and flour mixture until the butter pieces are all evenly coated with flour.
Add sour cream to the bowl.
Mix it into the butter and flour as you press down the fork making large clumps.
After a little mixing, use your hands to pull dough together. May be a bit shaggy but keep pressing it and it will form a ball. If dry, add drop more sour cream. Divide into balls.
Roll one out on a floured surface and lay into your pie pan.
Trim the edges to within 1/4-inch. Chill 30 minutes.
Add filling:
Mix first five ingredients and pile into bottom crust.
Dot with the butter.
Roll out top crust and place on pie.
Crimp and flute edges.
Brush with egg wash (1 egg beaten)
Sprinkle with sugar and cut a few slits in crust.
Bake at 425 for 20 minutes.
Then, lower oven to 350 and bake for 40-45 minutes.