Preheat your oven to 350°F (175°C). Grease a baking pan or line it with parchment paper.

In a saucepan over low heat, melt together the unsalted butter, granulated sugar, and cocoa powder until smooth, about 5 minutes. Let cool slightly, then whisk in eggs one at a time.

Sift together the all-purpose flour and a pinch of salt in a separate bowl. Gently fold this into the chocolate mixture until just combined.

Pour the brownie batter into the prepared baking pan and bake for 25-30 minutes, until a toothpick comes out with a few moist crumbs.

Cool the brownies in the pan for about 10 minutes before transferring to a wire rack. While cooling, melt the white chocolate chips.

Optionally mix black gel food coloring into the melted white chocolate and drizzle over the cooled brownies to create spider web patterns.