Preheat the oven to 350 °F. Prepare a 9x5 loaf pan but spraying it with non-stick cooking spray or greasing it with shortening or butter. Lay a strip of parchment paper across the width of the pan, leaving extra over the sides. Spray the parchment paper with non-stick cooking spray.
Using a large mixing bowl, add the whole wheat flour, bread flour, salt, baking soda, and rolled oats. Mix until combined. Add the brown sugar and mix thoroughly.
Make a well in the center of the dry ingredients and add the buttermilk, Guinness, melted butter, and molasses. Stir together until combined. The batter will be sticky.
Spread the batter in the prepared loaf pan, smoothing it evenly. Garnish with additional oats.
Bake for 55-60 minutes or until the internal temperature of the bread reaches 190 °F.
Remove the bread from the oven. Carefully pick up the loaf out of the pan by the overhanging parchment paper and allow it to cool completely on a wire rack, approximately 2 hours.
Notes
This recipe makes a large loaf but can be split into 2 smaller loaves.Test doneness with an instant-read thermometer. Since it is a large loaf, using a toothpick is difficult.The bread gains color as it bakes.Store completely cooled bread at room temperature in an airtight container.
This recipe was calculated using the exact brands and measurements I used to make this recipe. If you are following a strict diet please note changing anything will cause the nutritional info to change. My calculations are intended as a guide only.