I decided to totally master muffins so that I could whip up a batch in nothing flat. In the past couple of weeks I have baked a lot of muffins. Sometimes they "sink" in the middle but I can't figure out why. Two clues: 1. It only happens with muffins where the recipe has come from a "non professional" site [no problems with recipes from Epicurious, Food Network, etc.] and 2. It only happens when the leavening agent is baking soda.
Things I have tried:
1. Purchased new baking soda - didn't help.
2. Using cupcake papers vs greased pans - didn't help.
3. Never, ever open oven door - didn't help
4. Moving super quickly to get them in oven after combining dry & wet ingredients - didn't help
I am at a loss. HELP! I am fed up with muffins that taste great but look like ugly, little craters.