Crust: In a food processor, pulse gingersnap cookies into a rough powder. Stir in melted butter. Use the flat bottom of drinking glass (or your palm and fingers) to press crust mixture into the bottom and up the sides of a 9-inch pie plate. Cover and keep chilled in the fridge until ready to fill.
Blueberry Gelatin: In a small sauce pot, combine blueberries, sugar, and lemon juice. Set over medium heat and cook until sugar has dissolved and half of blueberries are still whole.
Meanwhile, bloom gelatin. Sprinkle gelatin over cold water and allow to sit for 5 minutes.
Remove blueberry mixture from heat. Stir in bloomed gelatin and stir until gelatin has dissolved. Allow mixture to cool to room temperature.* (see notes)
Whipped Cream Cheese: Using the bowl of a stand mixer fitted with a paddle attachment (or using an electric hand mixer), beat cream cheese and powdered sugar until smooth. Scrape down bowl as needed to ensure thorough mixing.
Add vanilla and heavy cream. Continue to beat until mixture has thickened to almost stiff peaks.
Assembly: Remove crust from fridge. Spread of thin layer of whipped cream cheese mixture over the crust bottom.
Gently fold chilled, thickened blueberry gelatin into whipped cream cheese mixture. Transfer to prepared crust. Cover with plastic wrap or store in an airtight container in the fridge for at least 3 hours (overnight is best).