In a medium bowl sift together the flour and salt. Set aside.
In the mixer with the flat beater beat together the butter, icing sugar and vanilla until creamy about 2-3 minutes. Add the flour mixture a little at a time, beat just until combined. Move the dough to a lightly floured flat surface and gently form into a ball.
Place the dough on a lightly greased 9 inch spring form tart pan or a cake pan lined with parchment paper. Flatten the dough evenly with the bottom of a glass (lightly floured) or the palm of your hand. Score the dough well with the tongs of a fork and make 10 slices halfway through the dough (do not cut all the way down).
Cover with plastic and refrigerate for 30 minutes to overnight.
Pre-heat oven to 300F (150C).
Bake for approximately 30 minutes. Let sit 5 minutes then again cut halfway through the cookie, let cool completely, remove from the pan (if using a springform pan then remove the bottom) and either drizzle or pour the glaze over the cookie, sprinkle with chopped almonds. Slice and serve.
In a medium bowl whisk together until smooth the icing sugar, juice and milk or cream. Add more or less cream depending on desired thickness.
When use the standup mixer I usually do my mixing on low speed (2 or 3).