1 T. plus 1 t. unsalted butter at room temperature
6 T. confectioners' sugar
To make the custard, place 1/2 cup plus 2 tablespoons of the milk, the cream,
and the sugar in a medium saucepan over medium heat. Bring just to a boil.
Dissolve the cornstarch and salt in the remaining milk in a small bowl. Whisk in
the egg yolk and then whisk into the hot-cream mixture. Whisk over medium-low
heat until thick, about 2 to 3 minutes. Remove from the heat and stir in the
vanilla. Transfer to a bowl, cover the surface with plastic wrap, and
refrigerate for 2 to 3 hours.
To make the cookies, preheat the oven to 400 degrees. Lightly spray several
baking sheets with nonstick cooking spray.
Whisk together the flours, baking soda, and salt in a small bowl.
In a medium bowl, beat the butter, sugar, vanilla, and lemon zest until light
and fluffy, about 2 minutes. Beat in the egg yolks and then the whole egg,
followed by the buttermilk. Fold in the flour mixture and stir until smooth.
Drop by generous tablespoons about 2 inches apart on the prepared sheets. Bake
for 10 to 11 minutes, or until the cookies are firm yet spongy to the touch. Let
cool.
Turn a cooled cookie upside down and spread with a rounded tablespoon of cooled
custard. Top with a cookie. Continue in this manner until there are no more
cookies.
To make the chocolate glaze, scald the cream in a small saucepan. Transfer to a
small bowl and add the chocolate and butter. Whisk until smooth. Add the
confectioners' sugar and stir until velvety.
Spread a scant tablespoon of chocolate evenly across the top of each
custard-filled cookie. Serve at room temperature.
Makes 13 cream-filled cookies.
Adapted from ``Rosie's Bakery Chocolate-Packed, Jam-Filled, Butter-Rich,
No-Holds-Barred Cookie Book,'' by Judy Rosenberg
