Dissolve baking soda in vinegar. Sift 2 cups flour with 1 teaspoon each of cinnamon, ground cloves, and ground ginger, and a pinch of sea salt.
Mix 3/4 cup molasses, 1 cup packed brown sugar, 2 eggs, 1/2 cup butter, and dissolved baking soda together in a large mixing bowl.
Stir in flour and spice mixture. The dough should be pretty stiff, but still sticky.
SCOOP AND BAKE METHOD: Scoop tablespoon-size mounds and place on a parchment-lined baking sheet. (see equipment for recommended scoop size)
ROLL AND BAKE METHOD: Divide the dough in half. Roll out one half at a time on a lightly floured counter to 1/4" thickness. Stamp with a cookie-cutter into 2" rounds. Use a dough scraper to lift the cutouts off the counter to a parchment-lined baking sheet.
Bake at 375°F for 8-10 minutes on a parchment-lined cookie sheet until cookies are set and just beginning to brown at the edges. Cool on a wire rack.
Once cookies are cooled, melt white chocolate in a double boiler until smooth. Spread melted chocolate on top of each cookie in a thin layer with the back of a spoon. Set on a wax paper-lined tray and allow to cool completely until chocolate is set.
Notes
Yields about 4 1/2 dozen (54 cookies). Servings are based on 2 cookies per person.
Rolling and cutting the dough will incorporate more flour into the dough in the process, so if using a scoop to measure out the dough and bake, more flour is needed for the dough.
I find that brown sugar helps to keep the cookies soft, but white sugar can also be used.
Adding vinegar to baking soda is an old-fashioned way of activating the baking soda if they didn't have baking powder. We still use the method to preserve the tradition.
Due to the dark color, it can be difficult to know if the cookie is done. It is best to test one or two at 8 or 9 minutes rather than over-baking so the cookies remain chewy.