Preheat the oven to 350°F (175°C) and prepare a baking pan.
Melt the butter in a saucepan over low heat.
Remove from heat and stir in the granulated sugar until well combined.
Add the eggs one at a time, mixing well after each addition.
Stir in the vanilla extract.
In a separate bowl, whisk together flour, cocoa powder, ground spices, and salt.
Gradually add the dry mixture to the wet mixture, stirring until just combined.
Pour the batter into the prepared baking pan and smooth the top.
Bake for approximately 25–30 minutes, or until a toothpick inserted comes out with a few moist crumbs.
Let the brownies cool in the pan before slicing.