Line two large baking sheets with parchment paper and set aside. Measure out the Rice Chex cereal into a very large mixing bowl.

In a microwave-safe bowl, combine the 12 oz white chocolate chips and coconut oil. Microwave in 30-second intervals, stirring between each, until completely smooth and melted (about 90 seconds total).

Stir the vanilla extract and coconut extract into the melted white chocolate until well combined and fragrant.

Pour the melted chocolate mixture over the cereal and gently fold with a rubber spatula until every piece is evenly coated. Work quickly as the chocolate begins to set.

Transfer the coated cereal to a large resealable plastic bag or paper bag. Add the powdered sugar, seal tightly, and shake vigorously for 30-45 seconds until all pieces are completely covered in white powder.

Spread the coated mixture onto the prepared baking sheets in a single layer. Let cool for 15 minutes at room temperature until the coating is completely set and dry to the touch.

Once cooled, transfer to a large bowl and gently fold in the shredded coconut, chopped dried pineapple, additional white chocolate chips, and lime zest if using.

Store in an airtight container at room temperature, separating layers with parchment paper if needed. The treat will stay fresh and crunchy for up to 2 weeks.