Ingredients:

• 1 (9") pie Plate
  

For the crust:

• 11 (2¼x4¾") graham crackers
• 2 Tbsp. sugar
• 1½ tsp. ground cinnamon
• Pinch kosher salt
• 6 Tbsp. unsalted butter, melted

For the filling:

• 1 (14-oz.) can sweetened condensed milk
• 4 large egg yolks
• 7 Tbsp. fresh Key lime juice
• 2 Tbsp. fresh lemon juice

For the topping:

• 1 cup chilled heavy cream
• 2 Tbsp. powdered sugar

 Directions:

Make the crust:

Step 1: Place rack in the center of oven and preheat to 350°F.

Step 2: Pulse graham crackers, sugar, cinnamon, and salt in a
food processor until fine crumbs form. With the motor running, drizzle in melted butter and process until well-combined. Transfer mixture to pie pan and press into bottom and up sides with a flat-bottomed measuring cup.

Step 3: Bake pie crust until golden brown and set, 8–10 minutes. Transfer to a wire rack and let cool to room temperature, about 15 minutes.

Make the filling and bake pie:

Step 4: Whisk condensed milk and yolks together in a large bowl. Add Key lime and lemon juices and whisk until well-combined (mixture will thicken slightly).

Step 5: Pour filling into crust and bake until center is just set, about 15 minutes. Transfer pie to a wire rack and let cool completely (filling will set as it cools), about 1 hour. Transfer to refrigerator and chill until cold, at least 1 hour.

Do Ahead: Pie (without topping) can be made, loosely covered, and chilled for up to 2 days.

Make the topping:

Step 6: When ready to serve, whip cream with a whisk or electric mixer to very soft peaks. Sprinkle sugar over cream and continue whipping until it holds stiff peaks. Dollop cream in center of pie (leaving at least a 1" border of visible pie filling) and serve.