1. Preheat your oven to 400°F (200°C) and line a baking sheet with parchment paper.

2. In a small bowl, combine the breadcrumbs, grated Parmesan cheese, and a pinch of salt, then set aside.

3. Melt 1 tablespoon of butter in a large skillet over medium heat, then add the garlic and cook for about 1 minute, until fragrant.

4. Add the shrimp to the skillet and cook for 2-3 minutes per side, until they turn pink. Remove them from the heat and set aside.

5. In the same skillet, melt the remaining 1 tablespoon of butter. Once melted, add the breadcrumb and Parmesan cheese mixture. Cook for about 5 minutes, stirring frequently, until the breadcrumbs are golden brown and crispy.

6. Arrange the sourdough bread slices on the prepared baking sheet, then divide the garlic shrimp among the bread slices, leaving a small border around the edges.

7. Sprinkle the toasted breadcrumbs and Parmesan cheese mixture evenly over the shrimp. If you want an extra kick, add a pinch of crushed red pepper flakes.

8. Bake in the preheated oven for 10-12 minutes, or until the bread is crispy and the shrimp are cooked through.

9. Remove the dish from the oven, sprinkle with chopped parsley, and serve immediately.