Preheat the oven to 350 degrees F. Line cookie sheet with parchment paper. Set aside.
In a large bowl, beat together butter and both kinds of sugar on high speed until light and fluffy. Add egg and vanilla extract and mix well. Add lemon juice, both extracts, and lemon zest and beat to combine. Stir in flour, baking powder, and salt until just blended.
Spoon the dough by tablespoons and roll into balls. Place on lined baking sheets. Slightly flatten each cookie with the bottom of a glass. Bake for 8-10 minutes until cookies are puffy.
While cookies are baking, combine 1/2 cup of powdered sugar and the packet of Kool-aid mix in a gallon-sized zip-top baggie.
When the cookies are finished baking, allow them to cool for 2 minutes then toss the cookies into the powdered sugar mix, a few at a time, until well-coated. Cool completely.