Let’s break down the process into easy-to-follow steps:

1. Make the Crust:

• Preheat the oven to 350°F (175°C).
• Combine the graham crackers and granulated sugar in a food processor and pulse until fine crumbs form. (Alternatively, crush the graham crackers in a zip-top bag with a rolling pin.)
• Pour in the melted butter and pulse until the crumbs are well coated and stick together when pinched.
• Press the mixture into the bottom and up the sides of a 9-inch pie plate.
• Bake until just set, about 10 minutes.
• Set aside to cool slightly, about 10 minutes.

2. Make the Filling:

• Whisk the egg yolks, condensed milk, Key lime juice, and lime zest in a medium bowl until combined.
• Pour the filling into the pre-baked crust.
• Bake until the center is set but still slightly jiggly, about 15 minutes.
• Let cool for 30 minutes, then refrigerate until chilled, at least 1 hour.

3. Make the Topping and Serve:

• Before serving, beat the heavy cream and powdered sugar in a large bowl with a mixer on medium speed until soft peaks form.
• Spread the whipped cream on the chilled pie.
• Garnish with lime zest.

These instructions are easy to understand.