Cook the chopped bacon in a large pot over medium heat for 6 to 8 minutes until it becomes crispy. Use a slotted spoon to transfer the bacon to a paper towel-lined plate, leaving the rendered fat in the pot.

Add the diced onion and celery to the hot bacon fat remaining in the pot. Sauté the vegetables over medium heat for about 5 minutes, stirring occasionally, until they are soft and translucent.

Sprinkle the flour over the vegetables and stir constantly for 1 to 2 minutes until a paste forms and the raw flour smell disappears. Slowly pour in the reserved clam juice and chicken broth, whisking constantly to prevent any lumps from forming.

Stir in the cubed potatoes and the bay leaf. Bring the mixture to a boil, then reduce the heat to low, cover the pot, and simmer for 15 minutes or until the potatoes are fork-tender.

Add the chopped clams and heavy cream to the pot, stirring well to combine. Cook uncovered over low heat for 5 minutes until the chowder is heated through and slightly thickened, being careful not to let it boil.

Season the chowder with salt and freshly cracked black pepper to taste, then discard the bay leaf. Ladle into warm bowls, top with the reserved crispy bacon, and serve immediately with oyster crackers.