Creating Chewy Chocolate Brownies is a breeze with these easy-to-follow steps:

1. Preheat Oven: Set your oven to 350°F (175°C) and grease a 9×13-inch baking pan.
2. Melt Butter: In a saucepan, melt the unsalted butter over low heat. Remove from heat and let it cool slightly.
3. Mix Sugar: Stir the granulated sugar into the melted butter until well combined.
4. Add Eggs: Beat in the eggs, one at a time, mixing well after each addition. Add the vanilla extract.
5. Combine Dry Ingredients: In a separate bowl, whisk together flour, cocoa powder, baking powder, and salt.
6. Mix Wet and Dry Ingredients: Gradually add the dry mixture to the wet mixture, stirring until just combined. Do not overmix.
7. Fold in Chocolate Chips: Stir in the semi-sweet chocolate chips and nuts if using.
8. Pour Batter: Spread the brownie batter evenly in the prepared baking pan.
9. Bake: Place in the preheated oven and bake for about 30 minutes. The edges should be firm, but the center might be slightly soft.
10. Cool: Remove from the oven and let the brownies cool in the pan for at least 5-10 minutes before cutting into squares.

With these straightforward steps, you will be on your way to enjoying these fabulous Chewy Chocolate Brownies!