Step 1: In a medium bowl, whisk together the flour, baking soda, ginger, cinnamon, cloves, nutmeg, and salt. Set aside.
Step 2: In a large bowl, using an electric mixer, cream together the softened butter and brown sugar until light and fluffy (about 2-3 minutes).
Step 3: Beat in the egg, then the molasses and vanilla extract, until well combined.
Step 4: Gradually add the dry ingredients to the wet ingredients, mixing on low speed until just combined and a soft dough forms. Do not overmix.
Step 5: Divide the dough in half, flatten each half into a disk, wrap tightly in plastic wrap, and refrigerate for at least 1 hour (or up to 3 days).
Step 6: Preheat your oven to 350°F (175°C). Line baking sheets with parchment paper.
Step 7: On a lightly floured surface, roll out one disk of chilled dough to about 1/4-inch thickness. Use Christmas tree cookie cutters to cut out shapes. Gather scraps, re-roll, and cut out more cookies.
Step 8: Carefully transfer the cut-out cookies to the prepared baking sheets, leaving about 1 inch between them.
Step 9: Bake for 8-10 minutes, or until the edges are lightly golden and the centers are set. Baking time may vary depending on cookie size.
Step 10: Let cookies cool on the baking sheets for 5 minutes before transferring them to a wire rack to cool completely.
Step 11: Once completely cool, decorate with royal icing, sprinkles, or any desired decorations. Let icing dry completely before storing.