Line an 8 x 8-inch deep baking dish or tray with parchment paper and set aside.
Place the Rice Chex cereal in a large mixing bowl and set aside.
In a microwave-safe bowl or small saucepan, combine the peanut butter, chocolate chips, maple syrup, and coconut oil.
Heat the mixture until melted—either in 20–30 second microwave bursts stirring between each, or over low heat on the stove—then whisk until smooth and fully combined.
Pour the melted chocolate mixture over the Rice Chex and gently fold until the cereal is evenly coated.
Transfer the coated cereal into the prepared pan, press evenly into an even layer, and refrigerate until firm, at least 1 hour.
Remove from the refrigerator, lift out using the parchment, and cut into 24 bars.