01 - Preheat oven to 350°F. Grease or line a 9x13-inch baking pan with parchment paper.
02 - In a large bowl, whisk together flour, brown sugar, baking soda, baking powder, salt, ginger, cinnamon, cloves, and nutmeg.
03 - In a separate bowl, combine melted butter, eggs, molasses, milk, and vanilla. Whisk until smooth.
04 - Pour wet ingredients into dry ingredients. Stir gently until just combined—do not overmix.
05 - Fold in half of the mini marshmallows, chocolate chips, and crushed cookies.
06 - Spread batter evenly into the prepared pan.
07 - Sprinkle remaining marshmallows, chocolate chips, cookie crumbs, and assorted candies on top, pressing them lightly into the batter.
08 - Bake for 28–32 minutes, or until the edges are set and a toothpick inserted in the center comes out with a few moist crumbs.
09 - Cool completely in the pan before slicing into bars.