Step 1

Line an 8x8-inch baking pan with foil or parchment paper. Set aside.

Step 2

In a medium heatproof bowl, combine chocolate and butter. Heat in the microwave for 30 seconds. Heat more, at 20-second intervals, stirring in between each interval, until melted. Stir in vanilla extract. Fold in marshmallows, nuts, and cookies.

Step 3

Spread mixture into prepared pan. Refrigerate for at least 2 hours, or until set. Lift from pan using the foil or parchment paper, and cut into squares. Keep in the fridge. I like to take it out of the fridge 15 minutes before serving.