Line an 8x8-inch square baking pan with foil. Spray foil lightly with cooking spray.

In a large mixing bowl, stir oats, blueberries, cinnamon and salt to combine.

In a small saucepan over low heat, heat peanut butter and honey, stirring often, 3-5 minutes until just warmed through. You could also do this in the microwave! Pour over the oats mixture; stir thoroughly to combine.

Using spatula, spread and press mixture firmly into prepared pan in even layer. Cover with foil; refrigerate 2 hours until cooled and set. Cut into bars. Store covered in refrigerator for up to 5 days.