Combine the butter and sugar in a large bowl and beat with a hand mixer until lighter in color and fluffy, for about 3-4 minutes.
1 cup unsalted butter, ⅔ cup granulated sugar
Beat in the egg, vanilla, almond, and lemon/orange zest (if using) until well blended.
1 large egg, 1 teaspoon lemon or orange zest, 1 teaspoon pure vanilla extract, ¼ teaspoon almond extract
In a separate bowl, whisk together the flour and salt.
2¼ cups all-purpose flour, ½ teaspoon kosher salt
Add the flour mixture to the butter mixture all at once and mix on low speed until just incorporated.
Lay out a baking sheet with parchment paper (waxed paper) and sprinkle a little flour on top.
Divide the dough equally into 2 portions (more if you have doubled the recipe). Using lightly floured hands, hold 1 portion of dough and gently shape it into a disc.
Place the disc on the floured paper, roll gently into a ¼-inch high oval or rectangle. Cut the cookie dough into shapes, and place cookies on parchment lined cookie sheets.Repeat the process until all the dough is used. Tightly cover the baking sheets with plastic wrap and refrigerate for at least 2 hours (or overnight).
When ready to bake, preheat oven to 350°F.
Space out the cut-out dough on parchment-lined cookie sheets and bake for 10 minutes, or until the edges begin to turn.
Take out of the oven, remove from the baking pan and cool on a cooling rack. Once completely cooled, the decorating can begin.