plus 2 tbsp flour • marshmallow fluff • pure vanilla extract • almond or soymilk • mild-flavored honey, such as clover • to 3 ounces finely chopped chocolate • margarine, cut into 1-inch cubes and frozen (if using salted margarine decrease salt slightly) • kosher or coarse sea salt (4 grams) • baking soda • dark brown sugar, lightly packed