Instructions:

Preheat your oven to 350ºF (180ºC). Prepare a 9x13 inch baking pan by lining it with parchment paper or greasing it with butter to prevent sticking.

In a medium saucepan, melt the butter and semisweet chocolate chips together over low heat, stirring until smooth. Remove from heat and let it cool slightly.

In a large mixing bowl, combine both the granulated sugar and brown sugar with the melted chocolate mixture, stirring until well blended. Add in the eggs, one at a time, mixing thoroughly after each addition. Then, stir in the vanilla extract.

In another bowl, sift together the all-purpose flour, cocoa powder, and salt. Gradually fold the dry ingredients into the chocolate mixture until just combined, being careful not to overmix.

Gently fold in the chopped nuts and any additional chocolate chips, if using. Pour the batter into the prepared baking pan and spread it evenly.

Bake in the preheated oven for 32-45 minutes, or until a wooden skewer inserted into the center comes out with a few moist crumbs. Be careful not to overbake, as this can lead to dry brownies.

Once done, remove the brownies from the oven and let them cool completely in the pan on a wire rack. When cool, lift the brownies out using the parchment paper and cut them into squares.

For the best brownie experience, consider toasting your nuts before adding them to the batter, as this enhances their flavor considerably.

If you prefer a less sweet brownie, feel free to swap some of the semisweet chocolate for bittersweet chocolate or adjust the amount of sugar to your taste.