Pour the Rice Chex cereal into a very large bowl and set aside.

Add the white chocolate chips, peanut butter, and butter to a medium saucepan.

Place the pan over low heat and stir constantly until everything is melted and smooth.

Don’t rush this step. White chocolate can scorch if the heat is too high, so low and slow is the way to go.

Remove the pan from the heat and stir in the vanilla extract and pumpkin pie spice.

Pour the melted mixture over the cereal.

Gently fold with a large spatula until the cereal is evenly coated.

Try not to crush the cereal.

Transfer the coated cereal to a large zip-top bag or large container with a lid. Add the powdered sugar and shake gently until all the pieces are covered.

Stir in the Reese’s Pieces candy.

Once completely cool, transfer to an airtight container.

It will keep at room temperature for about a week—although I doubt it will last that long!