Preheat the oven to 350 degrees F. Grease a 9x5 inch loaf pan with softened butter.In a medium bowl, whisk together the flour, sugar, baking powder, salt, pepper, and zest.Carefully pour the beer into the dry ingredients and stir until just combined. The dough will be thick and sticky. Transfer the dough into the prepared loaf pan. Evenly drizzle the melted butter over the top of the batter and then bake until golden on top, approximately 50 minutes.Allow to cool for 15 minutes before slicing.