The filling for this apple pie is on the tart side—experiment with less lemon juice or sweeter apples for a balance that's right for you. Most pie crusts use butter, shortening or lard to get a flaky texture—this one uses heart-healthy canola oil. We found that when we simply substitute oil for butter the texture suffers. The trick is to freeze the oil and a bit of flour together before incorporating it into the dough. The result is a flaky crust without all the saturated fat.