In a medium-sized bowl, whisk together the flour, cornstarch, baking powder, salt and baking soda until well blended.
In a large bowl, beat the butter, sugar and lemon zest together until pale and fluffy. Beat in the egg until well incorporated. Mix in the lemon juice, extracts and food coloring until well combined. Add the flour mixture and mix just until combined.
Refrigerate the cookie dough for 30 minutes to one hour.
Meanwhile, preheat the oven to 350ºF (180ºC). Line two large cookie sheets with parchment paper.
Roll the dough into balls, about 2 tablespoons each. I used a #30 portion scoop*. Roll the dough balls generously in powdered sugar.
Place the dough balls about 2 inches apart onto the prepared baking sheets.
Bake until the cookies are set, about 10-12 minutes. Let them cool on the cookie sheet for 1 minute then transfer to a cooling rack.