Preheat the oven to 350 degrees F and line a small baking pan with parchment paper.

Melt the butter in a mixing bowl, then stir in the sugar until combined.

Add the eggs and vanilla extract, mixing well after each addition.

Stir in the cocoa powder, flour, and salt until the batter is smooth and no dry streaks remain.

Pour the batter into the prepared pan and bake for 20 to 22 minutes until a toothpick comes out with moist crumbs.

Let the brownies cool completely in the pan.

Melt the white chocolate chips in a small saucepan over low heat or in short microwave bursts.

Transfer the melted white chocolate to a piping bag or zip-top bag with a small corner cut off, then pipe concentric circles on top of the cooled brownies.

Drag a toothpick from the center outward through the circles to form a spiderweb pattern.