Preheat your oven to 180°C (350°F) and lightly grease your baking dish or line it with parchment paper.
In a large mixing bowl, combine the rolled oats, brown sugar, and salt. Stir well to distribute evenly.
In a small saucepan, melt the butter over medium heat, then add honey and vanilla. Stir until the mixture is smooth and fragrant, about 2-3 minutes.
Pour the warm butter mixture over the dry ingredients in the bowl. Use a spatula to fold everything together until the oats are coated and sticky.
Transfer the mixture into the prepared baking dish. Use the back of a spatula or your fingers to press it down firmly and evenly across the surface.
Bake in the preheated oven for 20-25 minutes, until the edges turn a golden brown and the top looks slightly crisp.
Remove from the oven and let the bars cool in the dish for about 10 minutes, then transfer to a wire rack or leave in the dish to cool completely for 30 minutes.
Once cooled, use a sharp knife to cut into squares or rectangles. Wipe the knife between cuts for clean edges.
Serve the oatmeal bars at room temperature or slightly warmed. Enjoy their chewy, golden exterior and comforting flavor.
