Preheat the oven to 350 degrees F and line a small 6x6 inch baking pan with parchment paper.

In a small saucepan over low heat, melt the butter and semisweet chocolate together, stirring until smooth. Remove from heat.

Stir the sugar into the melted chocolate mixture until fully combined. Add the egg and vanilla extract, mixing well.

Whisk in the flour, cocoa powder, and salt until no dry streaks remain. Pour the batter into the prepared pan and spread evenly.

Bake for 20 to 22 minutes until a toothpick comes out with a few moist crumbs. Let the brownies cool completely in the pan.

Melt the white chocolate chips in the microwave in 20-second bursts, stirring between each until smooth. Spoon the melted white chocolate into a small zip-top bag, snip a tiny corner, and pipe concentric circles over the cooled brownies. Drag a toothpick from the center outward to create the web pattern. Cut into four squares once set.