• Cream the soft butter, lemon zest, and powdered sugar well, for at least 2-3 minutes, scraping down the bowl a couple of times. This aerates the dough for a lighter cookie.
• Blend in the lemon juice and egg yolk.
• Turn the mixer to low and blend in the flour and cornstarch until the dough comes together and there is no dry flour left. It will be soft and sticky.
• Form the soft dough into a flat disk and wrap in plastic wrap, smoothing out the surface as you wrap it.
• Put the dough in the refrigerator for 1 1/2 hours or in the freezer for 20 minutes to firm up.
• Preheat oven the 350F and line baking sheets with parchment paper.
• Roll out the dough to 1/4 in thickness on a lightly floured surface. If your dough is super cold it will soften as it sits at room temperature.
• Cut into rounds with a small 2 inch cookie cutter and place on a parchment lined baking sheets, one inch apart. If your dough has warmed up you may want to chill the cookies for 15-30 minutes before baking. I do a test cookie first to evaluate. If it doesn't spread, you're good to go.
• Bake for 11 minutes until set. The cookies will still be pale.
• I let the cookies cool for a few minutes on the pan before transferring to a rack to cool completely before glazing. Note: the cookies will be delicate when warm, but will firm up as they cool.

to make the glaze

• Stir together the sugar, strawberry powder and lemon juice until smooth and glossy. I don't find it necessary to use sifted sugar: if you have a few lumps in your glaze let it sit for a few minutes and stir again. Any small lumps should dissolve on their own. Note: if you want to thin your glaze just add a bit more lemon juice. To thicken it, add more sugar.
• Take each cooled cookie and dip headfirst straight down into the glaze, just touching all parts of the surface to the glaze. Lift the cookie straight up and let the excess glaze drip off. Turn the cookie upright and set on a rack. Note: if you have any trouble dunking the cookies you can also just spoon a small amount of glaze onto each cookie and spread it out gently to the edges.
• Allow the glaze to set up before eating or storing your pink lemonade cookies.
• Cookies will remain fresh for several days at room temperature, and can be frozen for up to 3 months.