Preheat oven to 350 degrees and line two cookie sheets with parchment paper.

Mix the flour, corn starch, baking soda and salt together in a bowl. Set aside.

In a stand mixer fitted with the paddle attachment, cream together the butter and sugar until light and fluffy.

To the creamed butter and sugar, add the eggs, lemon zest, lemon juice, vanilla extract and just ½ cup of the flour mixture to prevent curdling. Mix until well blended.

Mix in the remaining flour in 2 additions, stirring on low speed until the flour is just incorporated.

Stir in the white chocolate chips.

Using a ¼ cup, scoop out the cookie dough and drop onto the baking sheet. (I like my cookies to weigh around 55 grams each to keep them equal… a few grams on either side is fine).

Place the cookies far apart on the cookie sheet – no more than 4 per tray.

Bake at 350 for 10 – 12 minutes, until the edges of the cookies are just starting to brown.

Allow cookies to cool for 5 minutes on the tray, then carefully transfer to a wire rack.

Once completely cooled, dust with powdered sugar.