muffins

Dear Abigail I am not a regular baker. I am however able to cook properly. I have moved into an apartment with an oven that I am not sure is the culprit. I have a recipe for muffins which I have tried three times now with ingredients that are fresh, room temperature and correctly measured. The muffin when baked is barely higher than a thin biscuit. What other than the oven – I usually have it at 200C but am not sure of the temperature come setting. could this be the only problem.