Preheat the oven to 350 F. In a medium-sized bowl whisk together the flour, baking soda ground ginger, cinnamon, nutmeg, salt, and pepper.
Using an electric mixer (or stand mixer) on medium-high speed, beat brown sugar and butter in a large bowl, scraping down sides halfway through beating until light and fluffy, about 3 minutes. Reduce the mixer speed to low. Next, add the egg, molasses, and vanilla; beat just to blend. Last, add flour mixture; beat on low speed just to combine.
Using a 1½-oz. scoop (3 tbsp), portion out 16 balls. Place the dough balls on a parchment-lined baking tray and refrigerate for 1hr.
Divide the chilled cookie dough balls between 2 parchment-lined baking trays. Bake the cookies until the edges are firm and the centers appear cracked, 10–12 minutes then transfer the cookies to wire racks and let cool.
When the cookies are completely cool spread a heaping tablespoon of dulce de leche over each one then sprinkle with sea salt to serve.