Line your square pan with parchment paper, leaving overhang for easy lifting later.
In a large mixing bowl, combine the oats and honey or maple syrup. Stir well until the oats are coated and the mixture feels slightly sticky—this starts building the base for your bars.
Add the peanut butter and vanilla extract to the bowl. Mix thoroughly until everything is well combined and the mixture is smooth, with a chewy, cohesive texture.
Fold in the dark chocolate chunks and a pinch of sea salt, distributing them evenly throughout the mixture. The chocolate will start to melt slightly as you mix, creating melty pockets in the bars.
Transfer the mixture into the prepared pan. Using a spatula or your hands, press it firmly into an even layer, ensuring the mixture is compact and smooth on top. This helps the bars hold together nicely.
Place the pan in the fridge for at least 2 hours, or until the mixture is firm and set. If you're in a hurry, pop it in the freezer for about an hour to speed up the process.
Once chilled and firm, lift the entire block out of the pan using the parchment overhang. Place it on a cutting board and use a sharp knife to cut into equal squares or bars.
If desired, melt a little extra chocolate and drizzle over the bars or sprinkle with a few more sea salt flakes for added flavor and visual appeal.
Serve the bars immediately for a chewy, chocolatey treat or store them in an airtight container in the fridge for up to a week. For longer storage, freeze the bars and enjoy whenever craving hits.
