Preheat oven to 375°F (190°C).
Slice the top off of each bread bowl and gently hollow out the inside, leaving about a 1-inch border around the edges. Set the tops aside for serving.
In a large skillet, heat olive oil over medium heat. Add the chopped onion and garlic, sautéing for 2-3 minutes until softened.
Add the shrimp to the skillet and cook for 2-3 minutes until pink and opaque. Remove the shrimp and chop into small pieces.
Add the crab meat to the skillet and cook for another 2 minutes, just until heated through.
Lower the heat and pour in the heavy cream, stirring to combine. Add the Parmesan cheese, breadcrumbs, Old Bay seasoning, cayenne pepper, lemon juice, salt, and pepper. Stir until the mixture is smooth and heated through.
Fold in the cooked shrimp and crab mixture, then remove from heat.
Spoon the seafood mixture into the hollowed-out bread bowls, packing it down gently.
Place the stuffed bread bowls on a baking sheet and bake for 15-20 minutes, or until the bread is golden and the filling is bubbling.
Garnish with chopped parsley and serve with the reserved bread tops for dipping.