This is my beloved Nana's recipe, passed down from her mother who came to the U.S. from the Black Forest region of Germany.
My Nana herself was born and raised in Pennsylvania Dutch country. No matter where we moved, Nana and PopPop would pack up their car and come visit, bringing all the goodness we had left behind: sausages, scrapple, Cope's corn, Martin's hard pretzels, and best of all, Nana's homemade treats. Aluminum canisters held homemade sweet and salty wonders from Nana's kitchen including the Holy Grail of cookies: sand tarts.
Nana's sand tarts are THE holiday cookie in our family. Paper-thin butter cookies. Simple. Make ahead. Buttery crunch that quickly melts on your tongue. Great for a slice and bake hot cookie when friends drop by.
Bet you can't eat just one! —augustabeth
Cream butter and sugar until light and fluffy, stir in eggs one at a time, then vanilla. Mix in flour and salt.
Create frozen logs for slicing: lay out a 12-18" sheet of plastic wrap. Scoop out 3-4 dollops of batter and plop them in middle to make a horizontal log. Using a spatula, smooth into a rectangle shape. Roll plastic over the log, pressing out air bubbles on all 4 sides. Twist the short ends to seal tightly. Roll the plastic wrapped dough over the counter a few times to create a nice round cylinder or just keep the rectangle. Aim for a log the thickness of a small sand dollar (about 1 1/2" in diameter). Repeat with rest of batter. Recipe yields 3-4 logs. Freeze logs bags until ready to bake, at least 8 hours or overnight. Keeps in freezer several months if well wrapped.
Preheat oven to 350.
Remove a log from freezer. With a sharp or serrated knife, slice wafer thin discs and place on parchment lined sheet pans. If dough resists a thin slice or breaks, patch broken slices with other broken slice and shape with your fingers.
Push a piece of nut into the center of each cookie. For a cookie as pictured bake 8 minutes or so, rotating sheets halfway through, until edges just begin to brown. For a super crispy caramelized cookie, bake a couple minutes more. Watch closely, browns quickly.
Remove from oven, slide parchment off tray right away, and sprinkle with cinnamon sugar while hot.