Preheat oven to 375ºF. Line cookie sheets with parchment paper.
Whisk dry ingredients together in a bowl. Set aside.
In a stand mixer with paddle attachment, or electric beater, beat butter for 2 minutes on medium until light and fluffy.
With mixer on low speed, gradually add dry ingredients to the butter. Mix until well blended, scraping down side of bowl as needed for about 2-4 minutes.
Stir in assorted stuff until pieces are evenly distributed. Refrigerate dough for one hour.
Roll dough into walnut-sized balls and place 2” apart on the parchment-lined cookie sheet. Lightly press down on balls with the back of a spoon. Bake for 16-18 minutes. Cookies should be lightly golden on the bottom and edges.
Remove from oven and place 3-4 mini marshmallows on top of each cookie. Let sit for a few minutes and then transfer to cooling rack until completely cooled.
In a small bowl add 1/2 cup semi-sweet chocolate chips with 1 Tbsp shortening. Microwave on 20 second intervals, stirring after each, until melted and smooth enough to drizzle. Add more shortening if needed for the right consistency (Note: margarine will work too). Drizzle chocolate over each cooled cookie and allow to set.