In a large saucepan saute garlic, thyme and sage over low heat in two tablespoons olive oil until fragrant, seasoning well with salt and pepper.
Add mashed squash, milk and chicken broth. Add a pinch or two of nutmeg and cinnamon. Combine well, re-season with salt and pepper and simmer for 25-30 minutes.
While the soup is simmering saute the onions in a large skillet with enough olive oil to generously coat bottom of the pan over medium-low heat. Mix in a teaspoon of sugar and season well with salt and pepper. Cook until onions are tender and turn a golden brown.
Serve soup garnished with a generous amount of onion and bacon.