Preheat the oven according to the directions on the box of brownie mix. Spray a round springform pan with non-stick cooking spray and set aside.
Prepare the brownie batter and bake according to the directions on the box and until a toothpick inserted into the center of the pan comes out clean or with a few crumbs (not with wet batter). Place the brownie pan on a wire rack and allow the brownies to cool completely.
Once cooled, carefully run a thin knife or rubber spatula around the edge of the pan before releasing the brownies. Use a sharp knife to slice the brownies into 8 equal slices (like a pie).
Place the chocolate chips in a microwave-safe bowl. Microwave for 30 seconds, stir, and microwave for an additional 30 seconds as needed, until the chocolate is smooth and melted.
Use a butter knife to dab a bit of melted chocolate onto the back of two candy eyes and place them on a brownie slice.
Spread a bit of melted chocolate onto the bottoms of two pretzel twists and place them onto the top corners of the brownie slice to at as the reindeer's antlers.
For the reindeer’s nose, add a small dot of chocolate to each m&m and place them on the tip of the brownie slices.
Allow all the chocolate to set then serve and enjoy.
Notes
Store tightly covered or in an airtight container at room temperature for up to 4 days. If storing in layers, separate each layer with parchment or wax paper. For longer storage, refrigerate the brownies for up to 1 week.To get the cleanest cuts possible, chill the brownies in the fridge for an hour or two before slicing, use a sharp chef's knife, and wipe off the knife between each cut.