I have tweaked this over the years so that the filling doesn't need baking. I just LOVE this pie, but in my opinion, the crust is the BEST part of this pie. This has become a staple amongst my friends and family. Note** I don't add green food coloring, but you can if you want a "lime-colored" pie.
Make the crust first. Pulverize the gingersnaps (I put them in a food processor but you can place them in a ziplock bag and use a rolling pin). Combine crust ingredients in bowl, and press into pie plate. Bake at 350 degrees for 5 min. Cool crust before filling.
A note about Key Lime juice: AlWAYS use KEY limes...they're the little tiny ones. Don't use regular limes--it won't taste right. If you can get them, use FRESH limes to make your juice. If fresh key limes are NOT available...I use bottled Key lime juice. Nellie & Joe's or Mrs. Biddle's key lime juices are GREAT.
In bowl, add cream cheese and condensed milk. Beat with a mixer until light and fluffy-ish. Add juice and zest and beat until smoooooth. (reserve some zest for garnishing).
Pour filling into cooled Gingersnappy crust. Chill. Garnish with whipped cream, lime slice and sprinkling of lime zest...or do what I do and mix the zest in the whipped cream for a tangy twist!