Ingredients: for the cookies: ½ cup unsalted butter ⅓ cup vegetable shortening 2¾ cups all-purpose flour ¾ cup sugar 1 egg, beaten ⅓ cup full fat sour cream 1½ teaspoons baking powder Juice of 1 lemon for the icing: 2 large egg whites 2 tsp fresh lemon juice 3 cups powdered sugar food coloring (optional) Instructions: For the cookies -In the bowl of a stand mixer fitted with a paddle attachment, beat butter and shortening about 30 seconds or until softened. -Add sugar, egg, sour cream, baking powder, and lemon juice and mix until incorporated. -Scrape down the sides of the bowl. -With the mixer on low, slowly add the flour. Scrape sides as needed. -Divide dough in half. Cover and chill for 2 to 3 hours or until easy to handle. -Preheat oven to 375. -Roll dough on lightly floured surface to ⅛ inch thick. -Cut with desired cookie cutter, dipped in flour to prevent sticking. Place on parchment or foil lined baking sheet. -Bake at 375 degrees for 5 to 6 minutes or until edges are firm and very lightly browned (these will not turn golden, they should still be white in color) -Slide parchment paper with cookies attached onto counter top to cool for 5 minutes. -Remove to wire rack to cool completely before icing. For the icing -In the bowl of an electric mixer fitted with a whisk attachement (or a hand mixer) beat egg whites and lemon juice until frothy. -Add the powdered sugar and beat until combined and smooth. -Add food coloring, if desired, and beat until combined. -The icing needs to be used immediately, as it hardens. -Place in a piping bag fitted with a fine tip. -Trace the outer edge of the cookie with the icing -“Flood” the inside of the cookies with icing (go back and forth with the icing until it is mostly covered with icing) -Use a toothpick or an offset spatula to smooth out the icing and pop any air bubbles. -Allow to harden for at least 2 hours. -Store in an airtight container.