In a medium sized mixing bowl, beat together the butter, molasses, and dark brown sugar until just combined.
Then, beat in the egg and vanilla.
Add in the flour, baking soda, salt, and spices. Beat the mixture together just until the last streak of flour disappears and the dough is cohesive.
Pat the dough down into a rectangle, then cover tightly in plastic wrap. Let the dough chill in the fridge for at least 1 hour.
Take out the chilled cookie dough and place it on a lightly floured work surface. Roll it out until it is ¼" thick, then use a gingerbread cookie cutter to cut out the cookies.
Re-roll and repeat until you have used up the cookie dough. [Note: I got 32 cookies from this which equates to 16 sandwich cookies. You may make more or less depending on your cookie cutter size!]
Transfer the cookies to a parchment lined baking sheet, leaving about ½" between each cookie.
Use a small heart shaped cookie cutter to stamp out a heart in the center of half of the cookies.
Place the tray of cookies in the freezer for 10 minutes to firm up.
Preheat the oven to 350℉ / 175℃. Bake the cookies for 8-10 minutes, until they no longer look wet on top.