Heat the oven to 350°F (175°C). Line a 9 x 13-inch baking pan with parchment paper, leaving some paper overhanging the sides so the cooled brownies can be lifted out easily.

Whisk the melted butter and granulated sugar together in a large bowl. Beat in the eggs and vanilla extract until the mixture looks smooth and glossy.

Sift or whisk together the flour, cocoa powder, and salt in a separate bowl. Add the dry mixture to the wet ingredients and stir just until combined, taking care not to overmix.

Spread the batter evenly in the prepared pan. Bake for 25-30 minutes, until the center is set and a toothpick comes out with a few moist crumbs.

Cool the brownies completely in the pan. For especially neat cuts, chill them for 20-30 minutes before lifting them out and slicing into 24 rectangles or squares.

Use small dots of chocolate frosting or slightly cooled melted chocolate to attach two candy eyes and one red candy nose to each brownie. Insert two pretzel pieces at the top of each piece to create antlers, then allow the decorations to set before serving.