• Line an 8×8" square baking dish with parchment paper, and set it aside.

Make the Chocolate Peanut Butter Layer:

• - Melt the chocolate and peanut butter together, either in a microwave-safe dish or on the stovetop over low heat.

Make the Oatmeal Layer:

• - In a 5-quart saucepan, melt the butter over medium heat.
• - Stir in the brown sugar and sea salt until dissolved.
• - Add the vanilla extract and stir until combined.
• - Reduce the heat to low and add the oats. Cook on low for about 2 minutes, or until all the ingredients are well combined.

Assemble:

• - Press about half of the oatmeal mixture into the bottom of the prepared baking dish using a greased spatula. Reserve the other half to sprinkle on top.
• - Pour the chocolate peanut butter mixture gently and slowly over the bottom layer, reserving about 2-3 tablespoons to drizzle on top.
• - Very gently crumble the remaining oat mixture over the chocolate peanut butter layer and press it into place, ensuring the entire top is covered.
• - Drizzle the top with the remaining chocolate peanut butter mixture.
• Cover the dish and refrigerate for at least 2 hours or overnight, until the chocolate is set.
• Let the bars come to room temperature before cutting them into squares.
• Enjoy your delicious Chocolate Peanut Butter Oatmeal Bars!