Vanilla bean paste—is thicker and slightly more intense flavor than vanilla extract.
Butter—use unsalted if you can for better control. If using salted butter, back off on the salt a bit. Butter with the highest fat content yields the best flavor.
All-purpose flour— it’s extremely important to measure the flour correctly to obtain the right texture for the cookies. To measure, fluff the flour with a fork. Use a spoon to scoop into the measuring cup. Level off with the flat blade of a butter knife.
Cornstarch—helps with the formation of tender crumbs.
Sugar—for sweetness.
Egg yolks—to add richness, provide texture, make the dough pliable and less crumbly.
Sanding or sparkling sugar—optional. For decorating.
