If you notice that your almond flour seems excessively oily, it's a good idea to dry it out. Oily ingredients can cause cracked macarons. Most bags of almond flour I purchase don't need to be dried out. This is usually a rare case. To dry out your almond flour, preheat the oven to 200°F. Spread the almond flour on a parchment-lined baking sheet. Bake for 30 minutes, then allow the flour to fully cool before baking the macarons.