there are many reasons why your cake could have fallen in the middle somtimes it is because you have put too much of one ingredient in or there is not enough air You could have bumped your oven. This is because the butter and whatnot is denser and falls to the bottom. If you don't bump it, your cake will end up being as you wish for it to be.
yes without flour the cake wont rise.
Yeast.
the cake will NOT rise, stay flat.
yeast
Cakes rise when baked, whereas flapjacks do not. So, a flapjack is not a cake.
If you forget to add baking soda to a cake recipe, the cake may not rise properly and can end up dense, flat, and with a tighter crumb. Baking soda is a leavening agent that helps the cake to rise by creating bubbles in the batter when it reacts with acid. Without it, the cake may not have the desired texture and may taste slightly off.
It either helps whatever you're baking rise or make whatever you're baking soft and fluffy.
It comes under the heading of pie, because cakes rise, cheesecake does not.
Not every recipe calls for baking soda, but for the ones that do it interacts with the flour to rise and expand the cookies or cake.
Vinegar
helium
make the cake rise