Preheat the oven to 180°C (fan-forced). Line a large baking tray with baking paper.
Place bacon rashers on one side of the prepared tray and bake for 12 minutes. Meanwhile, toss the sourdough cubes with olive oil, garlic powder (if using), and a pinch of salt. After 12 minutes, flip the bacon and add the croutons to the other side of the tray. Continue baking for 8 minutes, tossing the croutons once, until the bacon is crisp and the croutons golden. Remove from the oven and drain bacon on paper towel. Once cool, crumble or chop.
To make the dressing, whisk together the egg yolk, mustard, garlic, anchovy, and lemon juice in a medium bowl. Slowly drizzle in the olive oil while whisking until emulsified. Stir in parmesan and season with black pepper if desired. Taste before adding salt — it may not be needed.
To cook the eggs, bring a small pot of water to a boil. Gently lower in the eggs and boil for 6½ minutes. Transfer to cold water to stop the cooking, then peel and halve.
To assemble the salad, combine the lettuce with most of the croutons, bacon, and parmesan in a large bowl. Drizzle over the dressing and toss gently to coat.
Top with halved eggs, anchovy fillets (if using), the remaining croutons and bacon, and a final sprinkle of parmesan. Finish with freshly cracked black pepper and serve immediately.