1. In the bowl of a stand mixer fitted with the paddle attachment, or by hand
in a bowl with a sturdy silicone spatula, cream the butter and salt together on
low speed until smooth, about 30 seconds.
2. In a separate bowl, whisk the egg yolks, gradually adding the sugar while
whisking, until the yolks are light and fluffy – about a minute. With the mixer
on low, add the egg yolks to the butter, stopping the mixer to scrape down any
butter clinging to the sides so it all gets incorporated.
3. Sift together the flour and baking powder in a small bowl, then stir that
into the creamed butter mixture until it’s completely incorporated. (Don’t
overmix it.)
4. Pat the dough into a rectangle about 1-inch (3cm) thick, wrap in plastic, and
chill for an hour.
5. Line two baking sheets with parchment paper. Have a pastry scrape or thin
metal spatula handy.
6. Cut the rectangle of dough in half and place one piece between two large
sheets of parchment paper. Roll the dough until it is between 1/3- to 1/2-inch
(1,25cm) thick. Peel off the top piece of parchment paper and, using a 2-inch
(5cm) round cookie cutter, cut out circles of dough, place them on the prepared
baking sheet at least 1/2-inch (2cm) apart.
7. Roll the second piece of dough, cut out circles, and put them on the other
baking sheet. Chill the baking sheets of cookies in the refrigerator or
freezer until firm.
8.oven to 350ºF Adjust the oven rack to the middle of the oven.
9. Beat the egg in a small bowl with the teaspoon of water. Remove one sheet of
cookies from the refrigerator or freezer. Brush the tops of the cookies with the
egg wash then use a fork to cross hatch a pattern on the tops of the cookies.
Bake the cookies until the tops are golden brown, about 15 minutes, rotating the
baking sheet in the oven midway during baking.
10. Remove the cookies from the oven and let cool on a wire rack. Brush the
second baking sheet of cookies with the egg wash, rake a pattern across the tops
with a fork, and bake them.