Preheat oven to 350°.
Spray a 5"x 9" loaf pan with cooking spray. Set aside.
Sift flour, sugar, baking powder, and salt together in a large bowl. Add beer and mix until combined(dough will be sticky). Place dough into loaf pan. Pour melted butter over top of loaf.
Bake at 350°, uncovered, for 50-60 minutes, or until top is golden brown and toothpick comes out clean from center.