In the bowl of a stand mixer, place cold egg whites; freeze for 15 minutes. (See Note.)

Heat an electric nonstick griddle with lid over medium-low heat (300°F/150°C to 325°F/170°C).

In a medium bowl, whisk together cold egg yolks, cold milk, oil, and vanilla until slightly thickened and frothy, about 2 minutes. Sift flour, baking powder, and salt onto egg yolk mixture; whisk until just combined. (Mixture should fall off the whisk in a slow stream.)

Return mixer bowl to stand mixer. Add cream of tartar; using the whisk attachment, beat at medium speed until foamy and almost at soft peaks. With mixer on medium speed, add granulated sugar in a slow, steady stream. Increase mixer speed to medium-high, and beat until stiff peaks form. (Be careful not to overbeat.) Using a balloon whisk, gently whisk one-third of meringue into egg yolk mixture until just combined. Using a silicone spatula, gently fold in remaining meringue until just combined.

Spray griddle with cooking spray. Using a paper towel, spread spray to coat griddle lightly but evenly.

Using a 1⁄4-cup spring-loaded scoop, scoop 4 scoops of batter onto griddle, gently spreading each with back of scoop to about 3 1⁄2 inches wide. Place a few drops of water close to edges of griddle, and cover with lid; cook until top of batter looks set and shiny and starts to dry around edges, about 5 minutes. Scoop another 1⁄4-cup scoop of batter on top of each pancake. Cover and cook until batter looks set and shiny and starts to dry around edges, 4 to 5 minutes, adding drops of water as needed. Using a 1 1⁄2-tablespoon spring-loaded scoop, scoop remaining batter on top of pancakes. Cover and cook until bottoms are golden brown, about 2 minutes, adding drops of water as needed. Gently turn pancakes, cover, and cook until golden brown, 4 to 5 minutes, adding drops of water as needed. Serve immediately with confectioners’ sugar, butter, and maple syrup as desired.