In a medium bowl, beat the butter and 2 tablespoons + 1 teaspoon of powdered sugar. Once well combined, add the lemon zest, juice and vanilla. Beat well. Next, sprinkle the flour, cornstarch and salt over the top. Beat the dry ingredients into the wet mixture carefully on low speed. The dough will be slightly crumbly.

Next, dump the dough out onto a sheet of wax or parchment paper. Shape it into a uniform log about 6" long. Then, put the dough closest to the long end of the paper, then begin rolling it up in the paper, shaping the dough as you go. Your dough log will be roughly 8" long. Twist the ends of the paper closed and refrigerate the dough log for 1 hour.

After one hour has elapsed, preheat the oven to the 350.

Unroll the dough, slice it into 12 even slices then place the cookies on a baking sheet.

Bake for 12-14 minutes, or until the edges of the cookies barely begin to turn golden. You won't see much color change, so look closely.

Remove the pan from the oven and let the cookies cool on the sheet for 5 minutes.

Meanwhile, have ready a shallow bowl with the extra powdered sugar for rolling. Roll each cookie in powdered sugar while still warm, and let the cookies cool before serving.