Melt white chocolate, butter, lemon curd, and lemon extract in a small saucepan over low heat, stirring constantly.

Pour Rice Chex into a large paper bag (grocery size) and pour melted lemon mixture over cereal. Fold the bag to seal and shake to coat cereal.

Cool slightly; then add half of the powdered sugar to paper bag and shake to coat.

Add remaining powdered sugar and shake to coat.

Spread out on cookie sheet to cool. Sprinkle with additional powdered sugar as desired.

Once completely cool, store at room temperature in airtight containers.