Preheat oven to 350 degrees F. Line a 9 x 13-inch baking pan with parchment paper, spray with cooking spray, and set aside.
Beat the sugar and butter together until light and fluffy. Add the eggs one at a time, and beat until well combined.
Add the extract and stir in the flour, hot chocolate mix, and salt. Stir in the crushed candy cane and half of the chocolate chips.
Pour into a prepared baking pan and spread out evenly with a silicone spatula.
Place in the oven and bake until the brownies begin to pull away from the sides of the pan and are set in the center, about 25 to 30 minutes.
Remove from the oven and sprinkle with the remaining chocolate chips and the mini marshmallows evenly over the top of the hot brownies.
Place a baking sheet over the top of the brownies so the chocolate and marshmallows will melt.
Let cool for at least 10 minutes before cutting. Cut into 24 squares and drizzle with chocolate syrup for even more chocolatey goodness.
Notes
Allow brownies to cool completely before cutting for cleaner edges and less mess.
Use the ends of the parchment paper to lift the cooled brownies out of the pan.
It is best to cut the brownies on a cutting board to avoid cuts in the base of the baking pan that will end up rusting over time.
Cut brownies into 24 small squares or 12 large squares depending on your needs.
Store cooled brownies in an airtight container, or covered with plastic wrap at room temperature for 3 to 4 days. These brownies do not need to be refrigerated.
To freeze leftover brownies, wrap in plastic wrap, then aluminum foil and place in a zipper top bag. Freeze for up to 3 months. To defrost, allow brownies to defrost at room temperature. Heat in the the microwave in 15-second intervals to melt the chocolate if desired.