For the Shrimp:Preheat the oven to 400 degrees.
Rinse shrimp under cold water and remove tails, if necessary. Drain well, pat dry with paper towels and place them on a rimmed baking sheet. Drizzle the shrimp with the olive oil and season with the garlic pepper and salt, to taste. Roast for 8 to 10 minutes, or until cooked through. Remove from oven and toss with fresh lemon juice.
For the Croutons:Preheat the oven to 350 degrees.
Combine the melted butter, olive oil, and garlic powder in a small dish. Place bread cubes on a rimmed baking sheet and toss with the butter mixture and Parmesan cheese. Bake for 7 to 10 minutes, stirring occasionally, until toasted.
For the Salad:Assemble salad by placing chopped romaine in a large serving bowl. Drizzle with some of the salad dressing and toss well to coat. Add about half the Parmesan and toss again. Top with roasted shrimp, croutons, and remaining Parmesan. Drizzle top of salad with a little additional dressing and serve remaining dressing on the side.