Add butter and sugar to the mixer’s bowl. Spread salt around the bowl. Set mixer to a speed of medium-low and mix until mixed.
Add vanilla and stir until thoroughly integrated (butter should be evenly incorporated), scraping down the bowl as necessary.
Add flour and mix until thoroughly mixed.
On a floured surface, roll dough to a thickness of 0.3 inches. Cut into squares or rectangles with a knife or use cookie cutter for desirable shape.
Transfer to baking sheets without greasing, spacing 1 inch apart. You can remove excess flour from scraps, compress it, and re-roll them.
Transfer baking sheets to the refrigerator for 30 minutes to chill. In the middle, preheat the oven to 350 degrees.
Bake one sheet at a time in the middle of the oven for 13 – 16 minutes, or until the cookies are just set. Tip: After 9 minutes, take the cookies from the oven and use a butter knife to slide the spread section back in and smooth up their edges.
Allow your Lorna Doone Cookies to cool for 15 minutes on the baking sheet. After that, transfer to a wire rack to cool. Repeat with the second baking sheet.
If the chocolate finish is selected as an option: Put chocolate into a microwavable dish.
Melt in 20-second increments at 50 percent power, stirring in between, until smooth and melted (or melt in a double boiler on the stovetop).
Dip cookies halfway into chocolate, then slide the bottom of the cookie along the edge of the bowl to remove extra chocolate. Transfer to baking pans lined with parchment paper and chill until firm.