In the bowl of your stand mixer on medium speed using the paddle attachment, cream together the ½ cup unsalted butter and 1 cup dark brown sugar.
Add the ½ cup sourdough discard, ⅓ cup unsulphured or dark molasses, and 1 egg. Mix on medium speed until just combined.
Add the 3 cups all-purpose flour, 1 tablespoon ground cinnamon, 1 tablespoon ground ginger, 1 teaspoon baking soda, ½ teaspoon kosher salt, ½ teaspoon ground allspice, and ½ teaspoon ground cloves. Mix on low speed until just combined.
Divide the dough into two pieces and wrap each piece in wax paper. Refrigerate the dough for at least three hours.
Preheat the oven to 325°F (165°C). Line a baking sheet with parchment paper.
Remove the dough from the refrigerator. On a lightly floured surface using a floured rolling pin, roll each piece out until it is ¼ inch thick. Use cookie cutters to cut out shapes and place them on a prepared baking sheet. Don't crowd the baking sheet. These cookies will spread slightly as they bake. Gather up the scraps and roll them out again to cut out more cookies.
Bake the cookies for 12-14 minutes. The tops of the cookies should look dry and set.
Allow the cookies to cool on the baking sheet for 5 minutes before transferring them to a wire cooling rack to cool completely.
Decorate using your favorite icing and decorations.
Notes
Storage: Baked Sourdough Discard Gingerbread Cookies can be stored in an airtight container at room temperature for two to three weeks.Tips
Make sure all of the ingredients are at room temperature. This ensures the ingredients mix evenly and will give you the best final texture.
Don't over-mix the dough once the sourdough discard and flour has been added. Over-mixing will create too much gluten and cause the cookies to be tough.
You must chill the dough for at least 2-3 hours before baking. Chilling also allows the flour to absorb more liquid further solidifying the dough. If the dough is baked without chilling it first, the cookies will spread while baking loosing their shape.
Roll the dough out evenly so that all of the cookies are the same thickness and cook evenly.
Line your cookie sheet with parchment paper to help prevent the cookies from sticking and make removal easier.
Don't crowd the baking sheet. These cookies will spread slightly as they bake.
For a crispier cookie, bake them for slightly longer (about 2-3 minutes more).
Allow the cookies to cool for 5 minutes before transferring them to a wire rack. They may fall apart if you try to move them too soon.
Let the cookies cool completely before decorating them. If you try to ice them when they are still warm the icing will melt.