– Preheat your oven to 350°F (175°C). Grease and line an 8×8-inch baking pan with parchment paper, leaving some overhang for easy removal.

2. **Melt Butter and Chocolate**
– In a heatproof bowl, combine the butter and chopped chocolate. Melt them together using a microwave in 30-second intervals, stirring after each interval, or over a double boiler until smooth. Let cool slightly.

3. **Mix Sugars and Eggs**
– In a large mixing bowl, whisk together the granulated sugar, brown sugar, and eggs until light and fluffy, about 2–3 minutes. This step creates that signature crackly top.

4. **Combine Wet Ingredients**
– Stir the melted chocolate mixture into the sugar-egg mixture. Add the vanilla extract and salt, mixing until smooth.

5. **Add Dry Ingredients**
– Sift in the flour and cocoa powder. Gently fold the dry ingredients into the wet mixture using a spatula until just combined. Be careful not to overmix. Fold in the chocolate chips if using.

6. **Bake**
– Pour the batter into the prepared baking pan and spread it evenly. Bake for 30–35 minutes, or until the edges are set and a toothpick inserted in the center comes out with a few moist crumbs (not wet batter).

7. **Cool and Serve**
– Allow the brownies to cool in the pan for at least 20 minutes before lifting them out using the parchment overhang. Slice into squares and enjoy!