For the salad:
For the dressing:
Preheat the oven to 450˚ F. Remove the crust from the baguette and cut into cubes, about ¾- to 1-inches. Combine the cubed bread in a bowl with the melted butter and toss to coat evenly. Spread in an even layer on a rimmed baking sheet and season with salt and pepper to taste. Bake about 6 minutes, tossing once or twice during baking, until the bread cubes are golden brown and somewhat crisp. Set aside to cool. Meanwhile, heat a large skillet to medium-high and cook the bacon until crisp but not burned. Transfer the bacon to a paper towel-lined plate and let cool.
In a large salad bowl, combine the toasted bread cubes, tomatoes, lettuce, and Parmesan. Crumble the cooked bacon over the top. Toss gently to combine. In a jar or small lidded container, combine the garlic, lemon juice, Greek yogurt, and buttermilk. Season with salt and pepper to taste. Portion the salad into serving bowls and drizzle each serving very lightly with the dressing.
*Make ahead instructions: For best results, this dish should be assembled just before it is served. However, all of the components can be prepped in advance so that all that is required before serving is a bit of mixing.