Line your square pan with parchment paper, leaving some overhang for easy lifting.
In a microwave-safe bowl, combine the cocoa powder, honey, nut butter, and vanilla. Microwave in 30-second bursts, stirring after each, until the mixture is smooth, glossy, and fragrant—about 1 to 2 minutes.
Add the rolled oats and chocolate chips to the melted mixture. Stir well with a spatula until everything is evenly coated and sticky, and the oats are starting to soften.
Transfer the mixture into your prepared pan. Use a spatula or damp fingers to press it down firmly into an even layer—this helps the bars hold together nicely.
Smooth the top with your spatula or the back of a clean knife for a clean finish. This also helps create a flat surface for slicing later.
Place the pan in the fridge and chill for at least 2 hours, or until the mixture is firm and set. For best results, leave it overnight.
Once set, lift the block out of the pan using the parchment overhang. Use a sharp knife to slice into 8 to 10 bars, wiping the knife clean between cuts for neat, clean slices.
Enjoy your chewy, chocolaty bars straight from the fridge or at room temperature. Store leftovers in an airtight container in the fridge for up to a week or freeze for longer storage.
