Preheat oven to 350°F (180°C). Cut apples in wedges and core. In a 10-inch oven-proof frying pan, sauté apples in 2-3 tbsp (30-45 mL) butter until lightly browned; remove from pan and set aside. Combine flour, salt and evaporated milk in a mixing bowl. Beat in egg yolks, one at a time; add melted butter.
In another bowl, beat egg whites with cream of tartar and pinch of salt until they hold soft peaks; beat in sugar and continue beating until whites hold stiff peaks. Fold into batter using rubber spatula.
Heat 2 tsp (10 mL) butter in the frying pan. Remove from heat and pour batter into pan. Arrange apple wedges over batter. Bake at 350°F (180°C) until pancake is set, about 20 minutes. Add syrup or icing sugar if desired.