Place a sheet of parchment onto a baking sheet and set aside. Add the Rice Chex to a large bowl and set it aside.
In a resealable bag, add the powdered sugar, cinnamon and kosher salt. Mix it all together with a fork.
In a small saucepan filled with a few inches of water, with a glass or stainless steel bowl nestled atop, set over medium-low heat, add the white chocolate melting wafers and coconut oil. Allow the chocolate to melt slowly and then stir it with a silicon spatula until smooth. Remove it from the heat and then add the vanilla bean seeds and stir it until combined.
Pour the melted white chocolate mixture atop the Rice Chex. Give it a good mix until evenly coated and then immediately transfer to the prepared resealable bag. Close the bag securely and shake it, until all of the Rice Chex is evenly coated.
Pour it on the prepared baking sheet and allow to dry and set for 30 minutes.