1. Prepare the Crust:

1. Preheat oven to 350°F (175°C). Grease a 9×13-inch baking pan.
2. Melt butter in a saucepan over low heat. Remove from heat and stir in sugar, eggs, and vanilla extract.
3. In a separate bowl, whisk together flour, cocoa powder, salt, and baking powder.
4. Gradually add the dry ingredients to the wet mixture, stirring until just combined.
5. Pour batter into the prepared pan and spread evenly.
6. Bake for 25-30 minutes or until a toothpick inserted in the center comes out with a few moist crumbs.
7. Allow to cool before slicing and serving.