In a large bowl, add the pretzels, almonds if using, pistachios if using, shredded wheat cereal, orange zest and pumpkin pie spice. Stir to combine.
Add the chocolate chips to a large microwave-safe bowl and microwave until melted (see Cook's Note). Immediately stir the chocolate into the bowl with the crushed ingredients. Stir until everything is fully coated.
Use your hands to form truffle-size forms on the prepared baking sheet. Allow to set and cool in the refrigerator. Store in an airtight container.
An alternative way to melt the chocolate is using a double boiler, making sure the bottom of the top bowl doesn't reach the water level in the bottom pot when it boils.