Preheat oven to 350 degrees. Use parchment paper or a silpat mat to line a baking sheet.
Cream the butter, brown sugar and granulated sugar in a stand mixer until light and fluffy (about 2-3 minutes). Scrape the sides of the bowl to make sure all ingredients are blended.
Add in the eggs, corn syrup and vanilla and beat until combined.
Add in flour, cocoa, cornstarch, salt and baking soda. Mix until all combined.
Cut large marshmallows in half.
Scoop out 20 equal cookie dough balls (they should be 1/4 cup of dough). Flatten each dough ball and place a marshmallow half in the center of the dough. Carefully, wrap the cookie dough around the marshmallow and roll it in your hands to seal it.
Press chocolate chips and chopped almonds all over the top of the cookie dough ball. You want to basically cover the top and sides with as many chocolate chips and almond pieces as you can.
Bake the cookies at 350 degrees or 12 minutes and then let cool on the baking sheet for an additional 15 minutes. Remove cookies to cooling rack.