Pastry Pie Crust

2 c. unbleached flour 

1/2 tsp baking powder 

1 & 1/2 tsp sugar 

1/2 lb butter (2 sticks), softened 

1 egg yolk 

1/2 tsp white vinegar 

water 

In large bowl, combine all dry ingredients; stir gently to blend. Cut in butter with pastry blender or 2 forks until well blended. Whisk egg yolk in glass measuring cup. Add vinegar & stir to blend. Add just enough water to make 3/8 cup liquid. Mix well. Make well in center of flour mixture. Pour in egg mixture. Stir gently until well blended. You may need to abandon the forks & use you hand to mix it thoroughly. The dough will be slightly wet, but should not be soggy or sticky. Add a bit of flour if necessary. Divide dough into 2 balls; flatten each into a disc. Place on sheet of plastic wrap & refrigerate for at least 2 hours. 

Spread a piece of wax paper on counter. Lightly flour. Turn out dough onto flour & coat evenly. Place another sheet of wax paper on top & roll to desired thickness. Keeping top sheet of wax paper in place, gently fold in half (lifting gently off bottom piece of wax paper), then in quarters. Place in center of 9 inch glass pie dish & unfold crust gently. Lift off wax paper. Trim to fit & pinch into shape. Fill & bake.