Dissolve 1 teaspoon baking powder and 1 teaspoon vanilla extract in 1/4 cup of milk.
Mix all the ingredients well. Knead for 5 minutes on a lightly floured surface. Shape into a round disk 1/4 inch thick, wrap in plastic wrap, and refrigerate for 1/2 hour. Roll out the dough to fit into 12 1/2 X 1 1/2 inch pie tin.
For the Pastry Cream:
Beat the sugar, cornstarch, vanilla and egg yolks with a wire whisk in a large saucepan.
Place on medium heat, add the milk, and whisk until the mixture comes to a boil and thickens. Remove from heat and refrigerate. Meanwhile make the filling.
For the Filling:
Beat all the ingredients well. Fold in the pastry cream. Pour into a prepared pie tin. Bake for 1 hour at 350°F
Allow to cool. This can be frozen and thawed to room temperature before serving.