Lightly spray a 9×13-inch pan with nonstick spray and set aside.
In a large pot over low heat, melt the butter and dissolve the salt.
Add 14 ounces of the mini marshmallows and stir until completely melted and smooth.
Remove from the heat. Stir in the vanilla extract and the chai powder.
Fold in the Rice Krispies cereal and the remaining 2 ounces of mini marshmallows until evenly coated.
Transfer the mixture to the prepared pan and gently press into an even layer. Avoid packing the treats too firmly.
Let cool for 1 hour before cutting into 16 squares.