Preheat oven to 425 degrees F.
Cut the red potatoes into wedges and toss with 2 tablespoon olive oil and 1 teaspoon salt. Spread the potatoes on a baking sheet and bake for 10 minutes.
Remove the sheet pan from the oven and add the shucked corn. Bake for another 10 minutes.
Meanwhile, make the spiced butter. Combine ½ cup melted butter with 1 tablespoon paprika, 1 tablespoon lemon pepper, 1 tablespoon garlic powder, 1 tablespoon onion powder, 1 tablespoon sugar, ½ tablespoon Old Bay seasoning, and ½ teaspoon cayenne.
Remove the sheet pan from the oven and add the clams and sliced sausage. Toss all of the ingredients with the spiced butter and spread it into one even layer. Place the sliced lemon on top of the clams and bake for another 10 minutes or until the clam shells open.
Squeeze the lemon onto the clam bake and garnish with chopped parsley. Serve with fresh lemon wedges if desired.