Preheat oven to 400° F (200° C).
In large bowl, beat eggs until light and become light yellow in color.
Mix in sour cream, and vanilla.
In medium bowl, mix together the sugar, flour and salt. Pour into egg mixture and stir.
Fold in raspberries, gently.
Pour into unbaked pie crusts
Bake 30 - 35 minutes
Make topping by mixing together the flour, brown sugar, and walnuts. Cut in butter.
When pie is done, sprinkle topping over the pie and return to the oven 10 - 15 minutes or until the top is a golden brown.