Line a sheet pan with foil. Make sure the foil goes over the rim of the pan to keep the pan clean.
Place bacon in a single layer on the foil and place in cold oven. Turn oven on to 350°F.
Flip bacon after 25-30 minutes. Cook for an additional 25-30 minutes and flip the bacon one more time 5 minutes before it is done cooking.
Remove bacon to a paper towel-lined plate and blot the grease off the top of the bacon.
Toast buns if desired. Spread 1 tablespoon of mayonnaise on each bun half.
Place 1 piece of leaf lettuce on bottom half of bun. Top with 2 tomato slices, 2 oz smoked trout, and 3 slices bacon. Place avocado slices (half of an avocado) on top half of bun and place top half of bun on top of bacon.