Preheat the oven to 350°F. Butter a 9-by-5-inch loaf pan. Roughly chop ¼ cup of rolled oats.
Evenly coat the bottom and sides of the pan with the chopped oats, tapping out any excess and reserving them for the top of the loaf. Set aside.
In a large bowl, whisk together the remaining ¾ cup of rolled oats, flour, baking soda, and salt. Make a well in the center of the dry ingredients. Add the melted butter, stout, buttermilk, molasses, and honey. Stir until just combined, being careful not to over mix. Transfer the mixture to the prepared pan, smooth the top with a small offset spatula, and scatter the reserved chopped oats over top.
Bake until a skewer inserted into the center of the loaf comes out clean, 45 to 50 minutes. Allow to cool for 10 minutes, then remove from the pan and transfer to a wire rack to cool completely before slicing.