Nutella Lace Cookies

Position racks in the upper and lower thirds of the oven and preheat oven to 350 F. Line 2 baking sheets with parchment paper.

Melt the butter with the sugar in a saucepan over low heat, stirring, until the mixture thickens and the sugar is almost dissolved, about 5 minutes. Transfer to a large bowl and stir in the oats, flour, vanilla and salt. Let the mixture cool 10 minutes, then stir in the egg white.

Drop 7 rounded tablespoonfuls of batter onto each prepared baking sheet, about 3 1/2 inches apart. Spread each mound into a 3-inch circle. Bake, switching the position of the pans halfway through, until golden brown, 12 to 15 minutes total. Then remove the pans from the oven and let cookies cool on the baking sheets until firm, about 3 minutes. Then carefully remove them from the pans using a thin metal spatula and transfer to a rack to cool completely.

Spread 1-2 tablespoons Nutella on the bottom of 7 of the cookies. Top with another cookie.

Note: When working with the lace cookies be very gentle. Because they are so thin they break easily.