Preheat your oven to 350°F (175°C). Grease a 9x9-inch baking pan or line it with parchment paper.
Make the Brownie Batter:
In a mixing bowl, whisk together the melted butter and sugar until smooth. Add the eggs and vanilla extract, mixing until fully incorporated.
Combine Dry Ingredients:
In a separate bowl, sift together the flour, cocoa powder, salt, and baking powder. Gradually fold the dry ingredients into the wet mixture until just combined.
Pour into the Pan:
Spread the brownie batter evenly into the prepared baking pan.
Add the Churro Topping:
In a small bowl, mix the granulated sugar and ground cinnamon. Sprinkle the cinnamon-sugar mixture evenly over the top of the brownie batter.
Bake:
Bake in the preheated oven for 30–35 minutes, or until a toothpick inserted in the center comes out with moist crumbs.
Cool and Slice:
Allow the brownies to cool completely in the pan before slicing into squares.
Optional Drizzle:
Drizzle melted chocolate or caramel sauce over the brownies for an extra touch of indulgence.