Prepare the baking dish by lining an 8x8 inch baking dish with parchment paper, allowing overhang for easy removal.

In a medium saucepan, melt together ½ cup of butter or refined coconut oil over medium-low heat, stirring frequently until fully melted and glossy, about 2-3 minutes.

Stir in ⅓ cup of coconut sugar and 1 teaspoon of vanilla extract, heating gently until the mixture begins to bubble, approximately 1-2 minutes.

Add 2 cups of oats, 1 teaspoon of ground cinnamon, and a pinch of fine sea salt, stirring thoroughly for 4-5 minutes until the oats are evenly coated and mixture thickens slightly.

Remove the pan from heat and press half of the oat mixture firmly into the bottom of the prepared baking dish.

In a small saucepan, combine 1 cup of dark chocolate chips with ½ cup of natural peanut butter over low heat, stirring continuously until smooth, about 3-5 minutes.

Pour the melted chocolate mixture over the pressed oat base and spread evenly, reserving 2-3 tablespoons for drizzling later.

Sprinkle the remaining oat mixture on top of the melted chocolate layer, pressing down gently, then drizzle reserved chocolate mixture over the top.

Refrigerate the assembled bars for at least 2 hours to firm up completely.

Once chilled, remove the bars from the baking dish and cut into squares or rectangles using a sharp knife.