Preheat the oven to 350 degrees F. In a small saucepan, heat the milk and 2 tablespoons butter together. Using an electric mixer fitted with a wire whip, combine the eggs and sugar together. Beat on medium-high speed for about 8 minutes, or until the mixture is pale yellow, thick and has trippled in volume. With the machine running slowly add the heated milk. In a mixing bowl sift the flour, baking powder, and salt together. Fold the flour mixture into the egg mixture and mix thoroughly so that there are no lumps and the mixture is smooth. Fold in the vanilla. Grease a 1/2 sheet pan with 1 tablespoon butter. Sprinkle with a tablespoon of sugar. Pour cake batter evenly into pan and bake for about 15 to 20 minutes or until the edges are golden and the cake springs back when touched. Cool for 2 minutes. Using a thin knife, loosen edges and flip out onto a piece of parchment paper. Peel the parchment paper from the cake. Replace with a new sheet of parchment and flip back into the baking sheet.