Preheat oven to 375°F. Butter a loaf pan and set it aside.
In a medium bowl, whisk together the flour, baking powder, granulated sugar, and salt. Set aside.
In a large mixing bowl, mix together 5 tablespoons of butter and beer.
Add the flour mixture to the wet ingredients. Mix until all the ingredients are just combined. Do not overmix.
Pour the batter into the prepared pan, spreading the dough evenly.
Brush the remaining 1 tablespoon of melted butter over the top of the loaf.
Bake in the preheated oven for 35 to 40 minutes. The bread will be ready when a toothpick inserted near the center comes out clean.
Cool the bread in the pan for 15 to 20 minutes before transferring it to a cooling rack for cooling completely.
Notes
Keep the bread in an airtight container at room temperature for 2 to 3 days, then refrigerate for up to 5 days. Alternatively, freeze sliced bread in a freezer-safe bag for up to 30 days.
You can freeze the bread. Slice and store it in a freezer-safe bag for up to 30 days.