1. Prepare your pan: Line an 8×8 inch baking dish with parchment paper, leaving an overhang on the sides. This will make it much easier to lift the bars out once they’re set. Lightly grease the parchment paper if desired, though it’s often not necessary with the overhang.

2. Melt the wet ingredients: In a medium microwave-safe bowl, combine the peanut butter, honey (or maple syrup), and melted butter. Microwave for 30-60 seconds on high, stirring halfway through, until the mixture is warm and smooth. Alternatively, you can heat these ingredients in a small saucepan over low heat on the stovetop, stirring constantly until well combined.

3. Add vanilla: Remove the mixture from the heat (or microwave) and stir in the vanilla extract until fully incorporated. The warmth of the mixture will help the vanilla distribute evenly.

4. Combine with oats: Pour the warm peanut butter mixture over the rolled oats in a large mixing bowl. Use a sturdy spatula or spoon to mix thoroughly until all the oats are evenly coated and there are no dry spots remaining. If using, fold in the mini chocolate chips at this stage.

5. Press into the pan: Transfer the oat mixture to your prepared 8×8 inch baking dish. Using the back of a spoon or your hands (lightly dampened to prevent sticking), press the mixture down firmly and evenly into the pan. Make sure it’s compacted well from edge to edge; this is key for bars that hold their shape.

6. Chill until firm: Place the baking dish in the refrigerator for at least 30 minutes, or until the bars are completely firm. The chilling time allows the butter and peanut butter to solidify, binding the oats together into sturdy bars.

7. Cut and serve: Once firm, use the parchment paper overhang to lift the entire block of bars out of the dish. Place it on a cutting board and cut into 12-16 squares or rectangles, depending on your desired portion size.