Cake help needed please

[Dreamtopia]

Hello, I’m trying to make a layer cake with fondant on the outside. I was going to do buttercream underneath and have done a thin buttercream crumb coat, but can I now use ganache as the layer underneath the fondant or do I have to do buttercream now I’ve done the crumb coat in buttercream, does anyone know please? Thank you

It would be spreadable consistency ganache by the way not pourable

If its spreadable yes you can but it may be really difficult to lay the fondant. Might be worth putting it in the fridge with the ganache layer then putting the fondant on. Good luck op.
Is it a chocolate sponge? What flavour fondant is it?
I love cake!

Thank you, I decided to make some Swiss meringue buttercream instead which is sadly failing me at the moment, it’s soupy so I’ve put it in the fridge and will try mixing it up again in a bit. It’s a vanilla cake with lemon buttercream and jam filling, and (hopefully) lemon Swiss meringue buttercream on the outside under pale yellow fondant. I’m going to do a pink chocolate drip on the top and decorate with buttercream flowers, white chocolate dipped strawberries with pink sprinkles and white and yellow meringue kisses. Will post a picture if/when successful, so probably in about a week at this rate