01 - Whisk together flour, salt, and sugar in a large bowl until thoroughly combined.
02 - Cut cold butter into flour mixture using a pastry cutter or fingertips until texture resembles coarse crumbs with some pea-sized butter pieces remaining.
03 - Gradually add ice water while mixing gently. Stop when dough just comes together. Divide in half, form into two discs, wrap tightly, and refrigerate for at least 1 hour.
04 - Roll out one dough disc on lightly floured surface to fit 9-inch pie plate. Press gently into plate, trim edges evenly, and refrigerate while preparing braiding strips.
05 - Roll remaining dough disc to approximately 1/4 inch thickness. Cut twelve long, even strips measuring about 1/2 inch wide.
06 - Group strips into three sets of four. Pinch tops together. Working with one set, label strips left to right as 1-2-3-4. Cross strip 1 over 2, under 3, then over 4. Repeat with new left-most strip until fully braided.
07 - Carefully transfer braids to chilled pie edge, pressing gently to adhere. Trim excess dough. Use small amount of water along crust edge to help seal if necessary.
08 - Refrigerate assembled pie for 15 minutes to firm crust. Preheat oven to 400°F.
09 - Beat egg with milk. Brush entire braided crust evenly with egg wash mixture using a pastry brush.
10 - Line crust with parchment paper and fill with pie weights. Bake for 12–15 minutes until golden brown. Remove weights and continue baking if additional crispness is needed.
11 - Fill and finish baking according to your chosen pie filling recipe.