Sugar free cakes - HELP NEEDED

There isn’t really any such thing as a “sugar free cake”. Any flour converts to sugar in the body. So anyone who can’t have sugar, like diabetics, limits there carbs…including cake. Cakes need sugar to help them rise and give flavor and texture. You need at least a minimal amount of sugar in your batter. You can add stevia, a natural sweetener for extra sweetness without adding all the amount of sugar required in your recipe. That being said, you do have a large dome. You said you replaced your fan. Are you baking your cakes in convection?? My oven does both, but I prefer using the straight baking setting. Bajes more evenly, less chance of doming. If you use convection to bake your cakes, drop your oven temperature by 25 degrees so your cakes won’t bake too fast.
Hope this helps.

Ty for your reply, my oven only has a fan, but i will also lower the temp to see if that helps x

I’m with June on the oven temperature. I often drop it just a teeny bit to get a more level finish. I assume you’re also using a raising agent (baking powder?). Sure you’re not using too much?

hello.
firstly try not to over mix your batter.some of the flours you are using are very heavy so you would need to add less……cook your cakes on high until it domes a bit then drop the heat to continue cooking slow.i also add a little foil folded in half and lightly place it on the top and leave room for air or it will steam too much and become a rock when cold.i also add a little water the the tray under the cake for a light steam ,it retains moister and makes the cake moist not dry.it also heaps it rise and cook slowly yet keep the rise with no cracking.it also depends on the method you use to make the cakes ,being melted method or whipped butter method.