Prepare a pan: Line an 8x8-inch baking pan with parchment paper, leaving some overhang for easy removal.
Melt wet ingredients: In a medium saucepan over low heat, combine the peanut butter and honey (or maple syrup). Stir frequently until fully melted and smooth.
Add flavorings: Remove from heat and stir in the vanilla extract and salt.
Mix in oats: Add the rolled oats to the saucepan and stir until well coated. If using add-ins (like seeds or coconut), fold them in now.
Press into pan: Transfer the mixture into the prepared pan and press it down firmly into an even layer using a spatula or the back of a spoon.
Melt chocolate: In a microwave-safe bowl, melt the chocolate chips in 30-second intervals, stirring in between until fully melted.
Top the bars: Pour the melted chocolate over the oat mixture and spread it into an even layer.
Chill: Refrigerate the bars for at least 2 hours or until fully set.
Slice and serve: Use the parchment paper to lift the bars out of the pan. Cut into 12 even squares or bars.