In a microwave-safe bowl, combine 1 pound of almond bark and 1 tablespoon of vegetable oil. Microwave for 2 minutes, stirring halfway through until the mixture is completely melted and smooth.

In a large mixing bowl, add 6 cups of Fruit Loops along with 1 cup of dehydrated mini marshmallows if using. Pour the melted chocolate mixture over the cereal, ensuring that every piece is coated.

Using a large spoon, stir the mixture gently to ensure all pieces of Fruit Loops are thoroughly coated in chocolate.

Next, sprinkle 1 cup of powdered sugar evenly over the coated cereal mixture and stir gently until fully incorporated.

Prepare a parchment-lined cookie sheet and carefully spread the coated mixture out in an even layer. Allow the Fruit Loop Puppy Chow to cool and dry at room temperature for about 15–20 minutes.

Once cooled to room temperature, transfer the Fruit Loop Puppy Chow into a gallon-sized bag or an airtight container for storage.