In saucepan heat water. Dissolve butter in water, then add flour and baking powder. Mix by stirring with only a wooden spoon, and then boil for 3 minutes. Remove from heat, and stir in partially beaten eggs. Continue stirring until the dough becomes a thoroughly mixed stiff ball. Divide the dough into two equal portions. Spread each half of the dough into an 8”x12” baking pan, and bake at 350 degrees for 30 minutes. Cool on racks. Note: For ease of removal from pans, line the pans with parchment paper.
Put milk into a 2 quart microwaveable container. Microwave on high power for 3 minutes. In a small bowl, mix together sugar, cornstarch and flour. Add dry ingredients to hot milk, and stir very well. Microwave for another 1˝ minutes, and stir well. Microwave for yet another 1˝ minutes, and stir well. Microwave more if needed for mixture to boil and thicken. Stir in butter and vanilla. After the butter is completely melted, stir in dried pineapple, if desired. Allow to cool completely before placing the filling between the 2 cake layers. Refrigerate for at least 12 hours before serving. Dust with powdered sugar as cake is being served.