Combine flour, salt, baking soda, baking powder, & pumpkin pie spice in a bowl.
In a stand mixer, beat butter, oil, & sugar until light & fluffy. Scrape bowl Add pumpkin puree & 2 eggs. Blend until combined.
Slowly add flour mixture. Scrape bowl. Add ⅔ cup water until just incorporated.
Grease a 9-inch bread pan lined with parchment on the bottom, & pour mixture inside. Bake at 350*F for roughly 1 hour until done in the center. Allow to cool in pan on a rack.
Prepare glaze by melting butter, brown sugar & milk in a bowl in the microwave for 30 seconds (cover bowl, in case it splatters.) Once butter is melted, whisk until sugar dissolves. Add ½ cup powered sugar & cinnamon to taste & allow to cool to room temperature. Pour glaze over pumpkin loaf once it has cooled down a bit.
Remove bread from pan once the glaze has solidified & the bread is completely cool. Peel off parchment paper from the bottom. Slice & serve.