Chop the graham crackers into crumbs, using a food processor, to equal 1 1/2 cups.
Add the melted butter, salt, and brown sugar into the food processor and combine.
Press the graham cracker mixture into the pie pan until evenly thick on bottom and sides. TIP: use a measuring cup to evenly press the mixture evenly in the pie pan.
Bake the crust for 10 minutes then cool.
Key Lime Pie Filling
Mix together the condensed milk, egg yolks, key lime juice, and lime zest until mixture is smooth.
Pour the filling into the baked graham cracker crust.
Bake at 325° F for 20 minutes. TIP: bake the pie until the top is set with a slight jiggle.
Remove the pie from the oven and cool on a wire rack for 2 hours, then cool in the refrigerator at least 4 hours or overnight.
Homemade Whipped Cream
Place the heavy whipping cream, powdered sugar, and vanilla into an electric stand mixer bowl and mix on medium-high speed with a whisk attachment until soft peaks start to form.
Serve the homemade whipped cream immediately or cover tightly and chill in the fridge for up to 24 hours.
Notes
Storage: store in fridge for 3 to 4 days . Cover tightly with plastic wrap or foil.Freeze: let the pie chill completely, wrap the entire pie tightly in plastic wrap and aluminum foil, then freeze for up to 1 month. To serve, that in the fridge overnight then add whipped cream or garnishes just before serving.