Sand Tarts: Crispy Amish Butter Cookies

1. Cream together butter and sugar until soft and combined
2. Mix in eggs one at a time.
3. Add vanilla extract, salt, and baking soda.
4. Mix in einkorn flour slowly and gently until just combined. Einkorn flour doesn’t like to be over-mixed. This will be a sticky dough but should come together somewhat solid- if it’s too wet, add a little more flour. 
5. Cover and refrigerate at least 4 hours. Overnight is best. 
6. Preheat oven to 350*F and line a baking tray with parchment paper.
7. On a very floured work surface, or between two sheets of plastic wrap, take a portion of the dough and start rolling it out. The dough gets sticky quickly, so keep the rest in the refrigerator as you work. The trick to a great sand tart is to roll the dough as thin as possible. 
8. Use a cookie cutter to cut. We recommend a 3 inch circle. Carefully transfer cookies to the baking tray. These cookies don’t spread much or at all, so 1 inch of space between is fine.
9. Separate egg white into a dish and, using a pastry brush, lightly brush the dough with egg wash. Not too much here, or you’ll end up with a fried egg on top!
10. Sprinkle cinnamon sugar or add half of a walnut or pecan on top.
11. Bake for 8-10 minutes, until the cookie edges are turning golden. 
12. Let cool on the baking tray at least 5 minutes before transferring to a wire rack.

Since the cookies are so thin, this dough goes a long way. Pull more dough out of the refrigerator to roll out while the first batch bakes, or separate the dough into portions and keep in the freezer for the next time you want a buttery Amish sand tart.