Begin by marinating the shrimp. In a large bowl, combine large shrimp with egg white, garlic powder, onion powder, salt, pepper, and paprika. Toss to coat evenly, cover and refrigerate for at least 1 hour.

In a saucepan over medium heat, melt unsalted butter. Add minced garlic and sauté until fragrant. Gradually whisk in heavy cream, cooking until thickened, around 3-5 minutes. Stir in grated parmesan cheese until smooth.

In a small bowl, mix melted unsalted butter, minced garlic, and salt to create garlic butter. Set aside for use on the bread.

Combine all-purpose flour with additional salt, pepper, and paprika in a shallow dish. Dredge marinated shrimp in the flour mixture and shallow fry in a skillet for 1-2 minutes per side until golden brown.

Preheat your oven to 400°F (204°C). Slice the crusty loaf of bread in half lengthwise and lay it on a baking sheet. Brush the cut sides with garlic butter and bake for 5-7 minutes until golden.

Spread prepared Alfredo sauce evenly across both halves of the toasted bread. Layer with mozzarella, fried shrimp, and crab meat, adding more mozzarella on top.

Return the assembled bread to the oven and bake for another 10-15 minutes until cheese is melted, bubbling, and golden. Keep an eye to avoid over-browning.

Remove from the oven and garnish with chopped parsley and red pepper flakes. Serve with extra Alfredo sauce on the side.