I have since adapted it and have found that it is most sublime when orange zest and orange juice are used in place of the lemon zest and juice. It tastes just like a yummy Creamsicle!
Preheat oven to 350
1 c. butter (2 sticks) softened
1/2 c. powdered sugar
1 egg yolk
zest of 1 small-medium sized orange
2 Tbs. fresh orange juice
2 Tbs. milk
2 1/4 c. flour
1/4 c. granulated sugar
Cream butter and powdered sugar.
Add juice & zest, egg yolk & milk. Mix until mostly combined.
Add flour at slow speed and mix until thoroughly combined. The dough will be stiff.
Line a cookie sheet with parchment paper.
Form dough into 1" balls and dip into granulated sugar. Place balls sugar side up on the cookie sheet. With the bottom of a drinking glass, gently flatten each ball to a thickness of 1/3".
Bake 11-13 min. @ 350 until cookies are slightly golden on the bottom.