Homemade Milano Cookies

Recipe from here. Requires 4 egg whites so might pair well with this chocolate chip cookie recipe that calls for 4 egg yolks.

Ingredients
1 stick unsalted butter, softened (113g)
2 cups confectioners' sugar
1 teaspoon pure vanilla extract
4 egg whites
1 ½ cups all-purpose flour
¾ teaspoon salt
For the ganache: 1 cup chopped chocolate, ½ cup heavy cream (I didn’t need quite this much ganache)

Instructions

  1. Preheat the oven to 350°F. Line two baking sheets with parchment paper.
  2. In a large bowl, cream the butter with the confectioners' sugar until light and fluffy.
  3. Add the vanilla extract and mix to combine.
  4. Add the egg whites gradually, mixing until fully incorporated. (note the original recipe suggested using an electric mixer, so that might work better)
  5. Add the flour and salt and mix just until incorporated. (might work better with an electric mixer)
  6. Transfer the batter to a 1-gallon ziplock plastic bag. Cut a ¼-inch opening at one of the bottom corners. Pipe the batter into lines 1½ inches long on the baking sheet, leaving at least 2 inches between each cookie. Tip: Draw lines with a straight edge on the parchment paper, then turn the paper upside down and use the lines as a guide.
  7. Bake until the cookies are set and the edges are pale golden, 9 to 11 minutes. Remove from the oven and cool completely.
  8. MAKE THE GANACHE: While the cookies cool, place the chocolate in a medium-size heat-safe bowl. In a small pot, bring the cream to a boil over medium heat. Pour the hot cream over the chocolate. Let it sit for 30 to 45 seconds, then stir to combine.
  9. ASSEMBLE THE COOKIES: When the cookies are cool, turn half of them over and spread 1 tablespoon (I needed much less, a thin layer was good) of the ganache onto the center of each upside-down cookie. Top with another cookie.