Weigh or lightly spoon the flour into dry measuring cups; level with a knife. Combine the flour, sugar, salt, and baking powder in a bowl; cut in shortening with a pastry blender until the mixture resembles coarse meal.

Make a well in the center of the flour mixture. Combine butter and boiling water; pour the butter mixture into the center of the well. Gently draw the flour mixture into the butter mixture until moist clumps form. Press dough into a 4-inch circle; cover and chill 30 minutes.

Slightly overlap two sheets of plastic wrap. Unwrap the dough; place on plastic wrap. Cover the dough with two additional sheets of overlapping plastic wrap. Roll the dough into a 13" circle.