That happens because of the chemistry of the cake and the way it bakes, but it's nothing really to worry about if otherwise the cake is okay. And this is NOT a dumb question.
Here's what I would do:
- Make lots of extra frosting.
- Cut the cake crosswise into two layers.
- Make a thick layer of frosting on top of the cut surface of the bottom layer.
- Turn the top layer upside down, so the hump is on the bottom.
- Place the top layer hump side down into the filling so that the new top (cut side) of that layer is now flat.
- Wipe off any filling that has squished out, and use it (or just more of the frosting, if nothing squished) to make a thin layer of frosting over the whole cake (this is known as a "crumb coat").
- Let that set, and then slather the rest of the frosting all over the cake.
Sure, it may end up looking a little funny when it's cut, but it will be just fine to show off before then, and anyway, if it tastes good, who cares? :lips:
I commend you for trying. :D All my husband ever makes for me is oatmeal, salad, and tea (not all at the same time :lol:).