Combine Ricotta cheese and cream cheese in a food processor. Pulse several time until it starts to combine, then process until creamy. While processing, slowly pour thawed lemonade concentrate through the feeder tube of your processor. While processing, add eggs, slowly pour in sugar and finally the flour. Process for 2 minutes, scraping down sides of work bowl once.
Place empty pie crust onto a rimmed baking sheet. Pour mixture into pie crust.
It will be pretty full, so be careful when you transfer it to the oven. Bake in preheated 350°F oven 47-50 minutes or until center is set.
Cheesecake batter will have risen but will relax as it cools.
Transfer to cooling rack; cool completely. Cover and chill 4 hours or longer.
In a mixing bowl fitted with the whisk attachment, beat the whipping cream and powdered sugar on medium-high until stiff peaks are formed. Spread topping on pie.