Prep: Preheat your oven to 350°F (175°C). Line a 9×13 inch baking pan with parchment paper, leaving an overhang on two sides for easy removal. Grease the parchment paper lightly.

Melt Butter: In a medium saucepan over low heat, melt the butter completely. Remove from heat.

Combine Wet Ingredients: Immediately add the sugar to the hot butter and whisk to combine. Allow the mixture to cool for a few minutes. Then, add the eggs one at a time, whisking vigorously after each addition until the mixture is thick and smooth. Stir in the vanilla extract.

Combine Dry Ingredients: In a separate bowl, sift together the flour, cocoa powder, and salt.

Make Batter: Gently fold the dry ingredients into the wet ingredients using a spatula, mixing only until just combined and no dry streaks remain. Be careful not to overmix. Fold in the chocolate chips.

Bake: Pour the batter into the prepared pan and spread it evenly into the corners. Bake for 25-30 minutes, or until the edges are set and the center is still slightly soft. A toothpick inserted into the center should come out with a few moist crumbs attached.

Cool: Allow the brownies to cool completely in the pan set on a wire rack. This is crucial for achieving the perfect fudgy texture and clean slices.

Decorate: Once completely cool, use the parchment paper to lift the entire brownie block out of the pan. Decorate with your choice of Halloween-themed frostings, sprinkles, and candies. Slice into squares and serve.