Preheat the oven to 450°F. Line an 8x5 loaf pan with parchment paper.
In a large bowl, whisk together the whole wheat flour, all-purpose flour, dark brown sugar, oats, baking soda, baking powder, and salt.
In a separate large bowl, whisk together the beer, buttermilk, melted & cooled butter, and vanilla.
Gradually add the dry mixture to the wet mixture, stirring to combine.
Pour the batter into the prepared loaf pan. Lower the temperature to 400°F then bake for 45 minutes.
Makes: 1 loaf, which results in 10 to 12 slices, depending on how thickly you slice the bread. Nutritional value for each slice is based on 10 slices. You can spread a dab of butter or lightly spray the inside of the loaf pan with baking/cooking spray before lining it with parchment paper. The butter or spray helps keep the parchment paper in place.Oven temp: Preheating the oven to a higher heat then turning the temperature down when it's time to bake the bread helps give the rising agents in the batter some extra lift. This helps create a taller bread. Storage: Store in an airtight container or bread box at room temperature for up to five days. You can also refrigerate the bread for up to one week.