Set a large skillet over medium heat. Add the butter. Once the butter is melted, add in the bread cubes. Toss well. Toast the bread cubes on all sides, tossing every minute for even browning. After 3 minutes, sprinkle the croutons with garlic powder, 1/2 teaspoon salt, and 1/4 teaspoon cracked black pepper. Continue turning and cooking another 3-4 minutes until golden. Remove from heat and cool.
For the Caesar Dressing:
Whisk the egg yolks, Dijon mustard, and 1 1/2 tablespoons lemon juice together in a small bowl. Slowly drizzle in both oils, while whisking the mixture vigorously. This emulsifies the dressing for a thick silky texture.
Finely mince the anchovy fillets and garlic together. Whisk the anchovies, garlic, and grated Parmesan cheese into the dressing. Taste, then whisk in another 1/2 tablespoon lemon juice if desired. Salt and pepper to taste.
For the Salad:
Chop the lettuce and place it in a large salad bowl. Drizzle two-thirds of the dressing over the lettuce. Toss well to coat. Add more dressing if needed, but do not drench the lettuce. Then toss in the croutons. Garnish with shaved Parmesan cheese if desired. Serve immediately!