Preheat oven to 350 F.
In the bowl of a stand mixer with the paddle attachment, beat the butter on medium speed until creamy.
Add 1/2 cup of powdered sugar and beat until light and fluffy, add 2 tablespoons of fresh lemon juice. Gently blend on low until incorporated, scraping down sides with a spatula as needed.
In a small mixing bowl combine the flour, cornstarch and salt. Whisk together. Add the flour in four batches to the creamed butter and lemon mixture. Blend on medium low until each is incorporated.
Add Summer Blend until just incorporated.
Place the cookie dough in a small bowl and cover with plastic wrap. Refrigerate for 1 hour.
Line a baking sheet with parchment paper.
Scoop a level spoonful of dough using a 1-inch cookie scoop. Roll each into a tight ball and place two inches apart on the parchment lined baking sheet.
If you want to make cookie discs, press each dough ball to the desired thickness using the bottom of a at glass covered with a small piece of wax paper.
Bake for 13 minutes, until lightly browned around the edges.
Slide the parchment paper and baked cookies onto a wire rack to cool.
Repeat with a new piece of parchment paper placed on a cooled cookie sheet.
Allow the hot cookies to cool for a minute then toss in 1 cup of powdered sugar to coat.
Cool completely on the wire rack.