In a medium bowl, whisk together flour, baking soda, baking powder, spices, and salt. Set aside.

In a large bowl, beat butter and brown sugar until light and fluffy. Mix in the egg, then molasses and vanilla.

Gradually add dry ingredients to wet, mixing just until combined. Dough will be soft and slightly sticky.

Divide dough in half, flatten into disks, wrap in plastic, and chill at least 1 hour.

Preheat oven to 350°F. Line baking sheets with parchment.

On a lightly floured surface, roll out dough to 1/4" thickness. Cut into shapes and place on sheets.

Bake 8–10 minutes, until edges are firm but centers still look soft. Cool on sheet 5 minutes before transferring to rack.

Decorate with royal icing, sprinkles, or powdered sugar once cooled!