preheat oven to 350°. prepare baking sheet by spraying with non stick baking spray or wiping pan down evenly with shortening

• Beat together sugars and butter, taking time to scrape down sides of the bowl. Add egg yolks one at a time. Add 3 tablespoons of the zest from the lemons/limes/oranges. Mix salt and flour together gradually add to butter mixture. Dough will be crumbly. Drizzle in 4 tablespoons citrus juice while mixing, scrape down sides of bowl making sure that everything is combined.
• Place dough in pan (12x15" pan, baking sheet type with low rim is what I used), lightly flour hands and then press dough evenly in to all corners of the pan.
• Bake at 350 degrees for 25 minutes. Allow to cool for 5 minutes in pan, then flip bars out on to parchment paper. Lay a sheet of parchment on top, if you have a large cutting board this will work as well, flip the bars out on to parchment paper.

  Let cool 10 minutes longer while you make the glaze.
• Whisk glaze together and drizzle glaze over top of bars, and sprinkle with the remaining citrus zest. Cut into squares, store in an airtight container.