Pour your cereal into your large mixing bowl and set aside. Try to keep it mostly intact and filter out the broken bits, if it matters to you.
In your double boiler or microwave-safe bowl, add the white chocolate chips, oil, lemon juice, lemon zest, and lemon extract.
Melt the chocolate, stirring constantly (if over a double boiler) or stirring every 20-30 seconds (if microwaving) until the chocolate is melted and the lemon is mixed in and smooth
Pour this mixture over the top of the cereal. Carefully fold it in, trying to minimize breaking the cereal further. Continue until the cereal is well-coated.
Divide the powdered sugar into thirds and mix one third into the cereal to coat. Repeat with each remaining third for a thorough coating.
Let sit for a few minutes to soak in and solidify, then enjoy!