1. Dice the bacon, yellow onion and slice the heirloom tomatoes, set aside.
2. Rinse and wash the butter lettuce, pat them dry with paper towel
3. In a frying pan add bacon and cook for 5-10 minutes until golden brown
4. In a bowl combine mayonnaise and garlic powder, set aside.
5. Once the bacon is browned add the onions and sauté until soft.
6. Once the onions are soft add the balsamic vinegar and worcestershire sauce, stir and add brown sugar and bring it to a boil.
7. Once it reaches to a boil, reduces the heat and simmer for 10-15 minutes.
8. Once done, transfer in a bowl and allow it to cool for 30-45 minutes.
9. Slice the baguette and remove little bread from the top.
10. Spread the mayonnaise on both the slices, place the butter lettuce, tomatoes, and the spread the bacon jam and spread it on the bottom slice.
11. Slice the avocado and place it in the bread and close it.
12. Serve the sandwich with a cup of hot coffee.