In a small sauce pan, melt the butter and then stir in chocolate chips. Stir until the butter and chocolate chips melt and mixture is smooth. .
Set aside and let cool.
In a large bowl, mix together the flour, cocoa powder, baking powder and salt. Set Aside
In a mixer with a paddle attachment, combine the sugar, eggs and extract together until well combined.
Once the chocolate and butter mixture is cooled, mix it into the sugar, eggs and extract.
Then gradually whisk the flour mixture into the chocolate mixture.
Roll dough into a ball and cover in plastic wrap and place into the fridge for 1 hour.
Remove dough from the fridge and preheat oven to 325F.
Line a baking sheet with parchment paper or a silicone baking mat.
Roll dough into 1 inch balls and flatten them on the baking sheet about 2 inches apart. Press them down in the middle so there is a dip in the center.
Bake for 10 minutes. Remove from oven. Top each cookie with three mini marshmallows. Place back into the oven for 2 - 3 minutes.
Let cool while you make the chocolate glaze.
For the Glaze:
In a medium bowl whisk together melted butter, cocoa powder, hot water and vanilla extract. Then slowly whisk in the powdered sugar until everything is combined.
Drizzle each cookie with the chocolate glaze, covering the marshmallows. While the chocolate glaze is wet, sprinkle each cookie with the sprinkles.