When you lower the temperature, things take longer to cook through and brown less quickly. The usual rule of thumb is: for every 10°C (about 20°F) lower, increase baking time by roughly 5–10%. So if a recipe says: 225°C for 25 minutes, and you can only do 200°C, that’s 25°C lower, about 10-15% more baking time. So you’d bake it for around 28-30 minutes, not 35. (35 minutes would likely over-bake it unless it’s something dense). bake 27–30 minutes, and start checking for doneness around 27 minutes. Some recipes tolerate the adjustment better than others.