Preheat the oven to 350 degrees. Line cookie sheets with parchment paper.
Place butter, unsweetened chocolate and 1 & 1/2 cups chocolate chips in a microwavable bowl and microwave in 30 second increments, stirring the chocolate each interval. Once melted and smooth, let cool.
Combine the flour, baking powder and salt in a small bowl and set aside.
Beat eggs, sugar and vanilla at medium with an electric mixer. Add dry ingredients, beating well. Add chocolate mixture and remaining chocolate chips.
Using medium cookie scoop, drop 1 inch apart onto a parchment lined baking sheet.Bake at 350 degrees for 10 minutes.
If you want the marshmallow on top of the cookie, 1 to 2 minutes before the cookies are done, add the marshmallow slice on top of the cookies.
Afterwards, take cookies out of the oven and add the chocolate kiss or peanut butter cup on top or you can add some chopped chocolate. You could also toast the marshmallow on top if you have a fire torch for a toasty marshmallow cookie.
Marshmallow Topped Cookies -Makes 2 1/2 Dozen Cookies