Preheat oven to 350 degrees. Roll out pie crust and sprinkle with parmesan and cayenne. Cover crust with a sheet of wax paper and press cheese and cayenne into crust by hand or with a rolling pin. Place pie crust into a 9 inch pie plate and crimp edges. In a small bowl stir together mayonnaise, lemon juice, basil and salt and pepper. Sprinkle 1/2 cup cheese in bottom. Top with 1/3 of the tomatoes and scallions. Sprinkle with more cheese and drizzle on 1/3 of mayonnaise mixture. Continue to layer tomatoes, scallions, cheese and mayonnaise and finish with cheese on top. Bake for 30-40 minutes until crust is golden and pie is bubbly. Allow pie to cool for 30 minutes. The pie will be easier to slice when it has completely cooled.