This is a simple alternative to a classic puff pastry. Use this when making our Carmelized Apple Galette.
Sift together all-purpose flour, cake flour, and salt into a large chilled bowl. Cut in butter pieces using a pastry knife until the butter is in very small lumps, about 1/2 inch in diameter.
Combine ice water and lemon juice, and stir into the flour mixture, a little at a time, pressing the dough together with your hands until it comes together.
Turn the dough out onto a well-floured work surface, and roll it into a 1/2-inch-thick rough rectangle, approximately 12 by 18 inches. The dough will be very crumbly. Fold bottom of the rectangle toward the center, then the top of the rectangle toward the center, overlapping the bottom third, like a letter, and give the dough a quarter turn to the right. Roll the dough into a large rectangle, 1/2 inch thick, and fold into thirds again. This completes the first double turn. Remove any excess flour with a wide, dry pastry brush. Repeat rolling, folding, and turning process two more times to execute another double turn, refrigerating the dough for a few minutes if the butter becomes too warm. Wrap the dough in plastic, and chill in refrigerator for 1 hour.
Remove chilled dough from the refrigerator. Repeat rolling, folding, and turning process again to execute one more double turn. There will be six turns in all. The dough needs to be rolled out to a 1/2-inch-thick rectangle each time. With each turn, the dough will become smoother and easier to handle. Store the dough, wrapped well in plastic, in the refrigerator for up to 2 days or in the freezer for 3 months.