Line a large baking sheet with parchment paper and set it aside.

Pour the Rice Chex into a large mixing bowl. If you have a bowl with a lid, use it so you can shake the cereal with the powdered sugar later.

Place the white chocolate and coconut oil in a microwave-safe bowl.

Microwave in 30-second intervals, stirring thoroughly after each interval, until the white chocolate is completely melted and smooth.

Pour the melted white chocolate mixture over the Rice Chex.

Add the lemon juice and lemon zest to the bowl.

Gently mix until the cereal is thoroughly coated with the white chocolate and lemon mixture.

Spread the coated cereal in a single layer on the parchment-lined baking sheet.

Allow the mixture to set at room temperature. To speed up the process, place the baking sheet in the refrigerator for approximately 10 minutes.

Once the coating has set, return the cereal to the mixing bowl and add the powdered sugar. Secure the lid and gently shake until the cereal is evenly coated. You can also place the cereal and powdered sugar in a large resealable plastic bag and shake it that way.

Break apart any large clusters and serve.