1. Weigh or lightly spoon flours into dry measuring cups; level with a knife. Combine flours, sugar, and next 3 ingredients (through salt) in a large bowl; stir with a whisk. Cut in butter and shortening with a pastry blender or 2 knives until mixture resembles coarse meal. Add milk; toss with a fork until moist. Gently press mixture in a 4-inch circle on 2 sheets of heavy-duty plastic wrap that overlap; cover with additional overlapping plastic wrap. Chill at least 2 hours.
2. Preheat oven to 375°.
3. Roll dough, still covered, into a 12-inch circle. Fit dough, plastic wrap side up, into a 9-inch pie plate coated with cooking spray. Remove remaining plastic wrap. Press dough against bottom and sides of pan. Fold edges under or flute decoratively.
4. Line bottom of dough with parchment paper; arrange pie weights or dried beans on paper. Bake at 375° for 12 minutes. Remove pie weights and paper; bake an additional 8 minutes or until edges are lightly browned. Cool on a wire rack.