From How to Measure Flour – Measuring Tips
“The most common mistake made in measuring flour is to dip the measuring cup into the flour instead of lightly spooning flour into the measuring cup. This can result in up to 25% more flour than the recipe calls for. To see this for yourself, measure 3 cups of flour into a bowl by scooping the flour with the measuring cup. Then stir the measured flour, and re-measure by lightly scooping with a spoon. When you have measured 3 cups this way, how much flour is left in the bowl? This extra flour will make your baked products heavy and tough. So remember to measure by lightly scooping with a spoon!”
Okay, this proves what an idiot I am.