1. Preheat your oven to 350°F (175°C) and lightly grease a 9×13 inch baking pan.
2. In a large mixing bowl, combine the melted butter, granulated sugar, and cocoa powder. Mix until smooth and creamy.
3. Add in the vanilla extract and eggs, one at a time, mixing well after each addition.
4. In a separate bowl, whisk together the flour, salt, and baking powder. Gradually add this to the wet mixture, stirring until just combined.
5. Fold in the chocolate chips and half of the Halloween-themed sprinkles. If using nuts, fold those in as well.
6. Pour the batter into the prepared baking pan, spreading it evenly with a spatula. Sprinkle the remaining sprinkles over the top.
7. Bake in the preheated oven for 25-30 minutes, or until a toothpick inserted into the center comes out with a few moist crumbs.
8. Allow the brownies to cool in the pan before cutting into squares. This is the hardest part because the smell is so tempting!

One trick I’ve learned is to line the pan with parchment paper with a bit of overhang on the sides. This makes it so much easier to lift the brownies out of the pan once they’ve cooled. It’s a little tip my grandmother shared during our many baking sessions together.