In a medium sized bowl mix the flour, cornstarch and salt. Set aside.
Whip the butter, sugar and lemon peel in the bowl of a stand mixer with the flat beater on until you get a creamy, pale and fluffy buttercream. About five minutes at medium high speed.
Add the dry ingredients and whip at medium low speed just until incorporated. Do not over mix. This will take about 10-15 seconds.
Wrap the dough in plastic and refrigerate for at least 2 hours, up to 2 days.
Meanwhile, prepare the glaze. Mix the powdered sugar, milk, lemon juice, vanilla extract and salt in a small bowl. Allow to rest for at least 2 hours at room temperature.
Preheat the oven to 350 F / 180 C. Prepare a baking tray with parchment paper. Unwrap the dough and roll in the tray until it is ⅛” thick. Using cookie cutters of about 3 ⅛” in diameter, cut 16-18 cookies. Create more cookies with the dough excess.
Bake the cookies for 12-14 minutes, or until edges are lightly golden. Let cool completely.
Dip the top of the cookies in the glaze and immediately decorate with dried flowers and freeze dried raspberries. Rest for 15 minutes until the icing hardens.