Key Lime Pie (no, I could not think of any clever title)

Here's the key lime pie recipe I use. I remember, a few years back, being intimidated by the idea of key lime pie, though I had made cheesecakes for a long time. I'm not entirely sure why, to be honest. Turns out it's easy as pie, so to speak.
This is for a 10 in. springform pan:

Filling:
15 eggs yolks (beaten slowly)
3 cans of sweetened condensed milk
1 1/2 C of key lime juice (regular lime juice is not the same)
zest of 1 lime

 Crust:
2 C graham crackers crushed ( I use a food processor)
6 oz melted butter
1/4 C sugar

Topping:
1 pint of whipping cream
1/4 C sugar
lime zest

Combine the crust ingredients, stir together and press firmly into the springform pan. Bake at 325° for 10 min and cool.

Beat the egg yolk slowly (I do it by hand, otherwise too much air gets mixed in), stir in the 3 cans of sweetened condensed milk, key lime juice, and about 3/4 of the lime zest. scrape into cooled crust and bake at 325° for about 40 minutes or until the center if firm and convex.
Cool completely. Whip the cream and spread on top, garnish with leftover lime zest.
*Most recipes don't call for the zest, but it really gives it a nice zing.
I apologize that the only pic I have is "pre topping", but use your imagination.
Buon Appetito!