Preheat your oven to 350°F (175°C) and line an 8x8 inch baking dish with parchment paper, leaving some overhang for easy removal.
In a large mixing bowl, combine the peanut butter, honey (or maple syrup), and vanilla extract. Mix together until smooth and creamy.
In another bowl, combine the rolled oats, protein powder (if using), chia seeds, dried cranberries, and salt. Stir until well combined.
Pour the dry mixture into the wet mixture and mix thoroughly until all ingredients are evenly combined.
Transfer the mixture to the prepared baking dish. Press it down firmly using a spatula or your hands to make sure it’s tightly packed.
Place the baking dish in the preheated oven and bake for 20-25 minutes until the edges are slightly golden.
Allow the bars to cool in the pan for about 10 minutes, then lift them out using the parchment paper overhang. Let them cool completely before cutting them into bars.
Store the energy bars in an airtight container at room temperature for up to a week or in the refrigerator for longer shelf life.
Notes
For a vegan option, substitute honey with maple syrup.