Set oven to 450°. Evenly coat baking dish with spray. Break eggs into bowl. Add milk, flour and 1 1/2 tablespoons sugar. Beat with whisk or fork until eggs, milk, flour and sugar are smooth. Pour egg mixture into baking dish. With oven mitts or potholders, put baking dish on center rack in oven and bake 12 minutes. After 12 minutes reduce heat to 375° and bake 8 minutes. Take baking dish out of oven.
While pancake is baking, put 1/3 cup sugar and cornstarch in saucepan. Stir with spoon until sugar and cornstarch are mixed together really well. Stir in water. Add peaches. Cook on medium heat, stirring until liquid boils all over. Keep cooking and stirring for one minute. Take pan off heat. Stir in extract, if desired. With pizza cutter, cut pancake into 8 pieces. Spoon 1/4 cup of peaches and syrup over each piece.