Melt butter in large saucepan over medium heat
Add onion, garlic and brown sugar; cook for 1 to 2 minutes or until soft
Add broth, water, salt and pepper; bring to a boil, stirring occasionally
Reduce heat to low; cook stirring occasionally for 15 minutes
Stir in pumpkin, evaporated milk and cinnamon
Cook, stirring occasionally for 5 minutes
Remove from heat and transfer mixture to food processor or blender in batches if necessary; process until smooth
Return to saucepan and serve warm
