Preheat your oven to 350°F (175°C). Combine the brownie mix, eggs, and oil in a bowl, stirring until smooth. Pour into a greased baking pan and bake for 25-30 minutes.

Once baked, cool the brownies in the pan for about 10-15 minutes, then transfer to a wire rack to cool completely (about 30 minutes).

Melt the white chocolate in a microwave-safe bowl in 20-second intervals, stirring until smooth; this usually takes about 1-2 minutes.

Once cooled, fill a piping bag with melted white chocolate and pipe concentric circles on the brownies. Use a toothpick to drag lines from the center outwards to create a spiderweb design.

Allow the brownies to sit at room temperature for 20-30 minutes to let the chocolate set before slicing.