1. Prepare the Cereal:
- Place the Rice Chex cereal in a large mixing bowl. Line a baking sheet with parchment paper and set aside.
2. Make the Salted Caramel Sauce:
- In a medium saucepan, combine the granulated sugar and water over medium heat. Stir gently until the sugar dissolves, then stop stirring.
- Cook the mixture until it turns a golden amber color, swirling the pan occasionally to ensure even caramelization (this takes about 5-7 minutes).
- Remove from heat and carefully whisk in the warmed heavy cream (it will bubble). Add the butter, vanilla extract, and sea salt, stirring until smooth.
3. Coat the Cereal:
- Pour the salted caramel sauce over the cereal in the bowl, gently tossing to coat evenly. Work quickly to avoid the caramel hardening.
4. Add the Powdered Sugar:
- Transfer the coated cereal to a large zip-top bag or a lidded container. Add the powdered sugar, seal, and shake vigorously until all the cereal is well coated.
5. Spread and Cool:
- Spread the coated cereal onto the prepared baking sheet in an even layer. Let it cool and harden for about 20 minutes.
6. Serve:
- Sprinkle with a pinch of extra sea salt for added flavor, if desired. Serve immediately or store in an airtight container.