In a stand mixer fitted with the whisk attachment, beat the egg whites over medium speed until soft peaks start to form, or you start seeing soft shapes in the egg whites as the whisk moves along. Pour in the confectioners’ sugar, 1/4 cup at a time. Continue beating until you achieve meringue consistency, the mixture is shiny, thick and you see deeply marked shapes as the whisk moves along. You can also tell if it’s ready, if you stop the mixer and raise the whisk, the mixture should hold stiff peaks. With a rubber spatula, spoon the meringue on top of the pie, spread along very gently, making waves or peaks as you cover the entire pie. Place on the baking sheet and into the oven for another 10 minutes or until the meringue has set and its top is lightly browned.