Preheat oven to 350 degrees.
Beat butter and sugar in a large mixing bowl till creamy.
Add flour, salt, and eggs. Beat till smooth. Add buttermilk, lemon juice, and vanilla and blend well. (Mixture may appear curdled.)
Pour filling into a 9" pie crust. I like to use a deep dish.
Place the pie pan on a cookie sheet and place it in an oven that has been preheated to 350°. Bake for 30 minutes.
Using a medium bowl and fingers, pinch together all streusel ingredients to create a crumble
Remove pie from oven and top the pecan streusel on top
Place back into the oven and continue to back for 20 minutes
Allow cooling on a cooling rack for 30 minutes
Cut the tip of the piping bag and drizzle the salted caramel over the pie
Cut and serve!