Tip:Although I shape these cookies by hand, they can also be formed with a cookie press or pastry bag so they look like traditional spritz cookies. Brush the tops with the egg white and sprinkle with just the sugar, eliminating the crystallized ginger.
Position a rack in the center of the oven and heat the oven to 350°F. Line three large cookie sheets with parchment or nonstick baking liners.
In a large bowl, combine the butter, 3/4 cup of the sugar, the grated ginger, lemon zest, and salt. Using an electric mixer set on medium speed, beat the mixture until well blended and light, 2 to 3 min. Scrape the bowl. Add the egg yolks and vanilla; continue mixing until well blended, 30 to 60 seconds. Add the flour and mix on low speed until the dough is blended and just comes together.
Shape tablespoonfuls of the dough into 1-inch balls (I use a small ice cream scoop) and set the balls 1-1/2 inches apart on the prepared cookie sheets. In a small, shallow dish, mix the crystallized ginger and the remaining 2 Tbs. granulated sugar until blended.
With the palm of your hand, press on one of the dough balls until it’s 1/4 inch thick and about 2 inches in diameter. Repeat with remaining dough balls. Brush the tops of the cookies with the egg white and sprinkle them with the ginger-sugar mixture. Press gently on the cookies with the bottom of a metal measuring cup to help the topping adhere.
Bake one sheet at a time until the cookies are light brown on the bottoms and around the edges, about 11 min. on dark cookie sheets, or about 13 min. on silver-toned sheets. Set the sheet on a rack to cool for 5 min. and then transfer the cookies to the rack to cool completely. When cool, store in airtight containers.
Ginger flavor intensifies with time, making these cookies excellent candidates for long keeping. When stored in an airtight container, the cookies remain impressively delicious for up to five days from baking. Well wrapped, the cookies will keep for several weeks in the freezer.