This authentic key lime pie starts with a homemade graham cracker crust, then a creamy sweet and tart filling, and fluffy toasted meringue. This is a cool and refreshing dessert, and perfect for summer!
Combine graham cracker crumbs, brown sugar, and melted butter. Stir together ,then pour crust ingredients into pie dish, and push the crust into the bottom and up the sides of the dish. Bake for 10 minutes and let cool on a wire rack.
Bring the mixture to a boil, whisking constantly. Whisk for another couple of minutes until mixture thickens and coats the back of a spoon. Remove from heat and immediately add cold butter, lime zest, and vanilla.
Beat egg whites in a large bowl until frothy. Add cream of tartar and continue beating until stiff peaks form. Add sugar in until meringue is stiff and glossy.