Heat over to 400 degrees. In large bowl toss together pumpkin, 1/4 cup of oil (more or less as desired), sugar, thyme, salt and pepper. Place on an oiled sheet pan (and/or silpat) in over for ~15 minutes, until softened and light golden brown.
In saute pan over medium heat, render the bacon. After ~ 1 minute add garlic and onion. Saute for an additional 4-5 minutes until onions start to brown. Add vinegar, stir the mixture, remove from heat. Mix together onion mixture and pumpkin.
Crostini: Pour portion of oil on plate, and dip one side of each baguette slice in oil and then place (oil up) on sheet pan. Season with salt and pepper if desired, bake in over for ~10 minutes until golden brown. Spread (or place slices) of brie on each crotini lightly, put pumpkin mixture on top, and (if desired) sprinkle with roasted pumpkin seeds.