Grease a a 9x13" baking pan with cooking spray and then line with parchment paper, leaving some overhang for easy removal.

In a medium bowl, add the peanut butter and honey. Microwave for ~30 seconds to get them warmed a little bit to make them easier to mix.

Add the vanilla and then whisk well together, stirring until smooth.

In a large bowl, mix together the rolled oats, ground flaxseed, hemp hearts, and salt.

Pour the peanut butter mixture over the dry ingredients and stir until everything is evenly combined.

Press the mixture firmly into the prepared pan, spreading it evenly.

In a small bowl, add the chocolate chips and butter.

Microwave for 45 seconds and then intervals of 15 seconds, stirring between each interval, until the chocolate is smooth.

Spread over the bars and then sprinkle with sea salt.

Refrigerate for 30-60 minutes, until the chocolate is set.

Lift the bars out using the parchment paper, slice into squares, and serve.