Preheat oven to 375°F. Lightly grease a 9x5 bread loaf pan; set aside.
In a large mixing bowl, whisk together flour, sugar, baking powder, salt and garlic powder. Mix in cheese and pepperoni, stirring to coat.
Make a well in the center and add the beer. Stir just until combined. Do not overmix.
Take 2 tablespoons of the melted butter and pour into bottom of bread pan in an even layer. Spoon dough into pan and level smooth with a spatula.
Top bread with remaining 2 tablespoons of melted butter, then sprinkle with parmesan and Italian seasoning.
Bake for 40-50 minutes, or until a toothpick inserted in the top comes out clean or with a few crumbs. Remove from pan and let cool on a wire rack. Slice bread or cut into cubes, serve warm with marinara sauce, if desired.