Now, let’s dive into the fun part—making these scrumptious brownies! Follow these simple steps, and you’ll have a batch of molten lava brownies in no time.

1. Preheat the Oven:
   Start by preheating your oven to 425°F (220°C). This high temperature is crucial for achieving that molten center.
2. Prepare Your Baking Dish:
   Grease a 9×9-inch square baking pan with non-stick spray or butter, and line it with parchment paper for easy removal.
3. Melt the Butter and Chocolate:
   In a medium saucepan over low heat, combine the unsalted butter and chopped semisweet chocolate. Stir frequently until melted and smooth. If you prefer, you can also melt them in the microwave in short bursts, stirring in between. Just be careful not to burn the chocolate!
4. Mix the Sugars:
   Once the chocolate mixture is smooth, remove it from the heat. Stir in both granulated and brown sugar until well combined.
5. Add the Eggs:
   Allow the mixture to cool slightly, then add the eggs one at a time, mixing well after each addition. This helps create a fluffy texture.
6. Incorporate the Vanilla:
   Pour in the vanilla extract and mix until just combined.
7. Combine the Dry Ingredients:
   Gently fold in the flour and salt using a spatula. Be careful not to overmix; you want the batter to be thick and fudgy, but it should still have some lumps.
8. Pour into the Baking Dish:
   Pour half of the brownie batter into the prepared baking pan. Use a spatula to spread it evenly across the bottom.
9. Create the Lava Center:
   To achieve that molten center, you can either spoon dollops of chocolate ganache or place a few squares of chocolate directly on top of the batter. Then, pour the remaining brownie batter over the top, spreading it to cover the ganache or chocolate squares.
10. Bake:
    Place the pan in the preheated oven and bake for 15-20 minutes. You want the edges to look set while the center remains slightly soft. The toothpick test is essential here; insert one into the center, and it should come out with a few moist crumbs.
11. Cool and Serve:
    Once baked, remove the brownies from the oven and let them cool in the pan for about 10 minutes. Then, carefully lift them out using the parchment paper. Allow them to cool slightly before cutting into squares. Dust with powdered sugar if desired.