Step 1

Preheat oven to 375 degrees.

Step 2

In the bowl of an electric mixer fitted with the paddle attachment, combine walnuts, butter, sugar, flour, salt, yolk, and vanilla. Beat until well combined. Firmly press into the bottom and up the sides of a 10-inch or 11-by-8-inch fluted tart pan with a removable bottom. Freeze until firm, about 30 minutes. Bake until edges are set and golden, about 40 minutes. Remove from oven and let cool completely on a wire rack.