Preheat oven to 350°. Use about 2 tsp of butter to generously grease a loaf pan.
In a large bowl whisk together the flour, baking powder, salt, and sugar.
The easiest way to measure your wet ingredients: In a measuring cup, measure out 6 oz of beer then add your pumpkin until it reaches the 12 oz mark (1.5 c) with all pumpkin submerged. Add molasses and mix together.
Melt the remaining butter in the microwave or a small pan on the stove.
Add wet ingredients to the dry, stirring with a spatula or wooden spoon. The batter will be stickier than a bread dough but thicker than a muffin mix or typical quick bread batter.
Spread evenly into your prepared bread pan taking care to press the dough into the corners. Pour the melted butter on top.
Bake for 45-55 minutes, or until a knife inserted into the middle comes out clean and the butter is mostly absorbed by the bread.
Allow to cool for at least 10 minutes before slicing.