I use seriouscakes yellow cake recipe all the time. However, now one of my cakes has a boiled look at the bottom. It still taste good and the texture on top is fine. However, when you get towards the bottom it has a clay feeling, sort of rubbery. Does anyone know why it came out like that, or what i can do to fix it?

Not cooked through properly? If it's a recipe that normally turns out fine for you, could there be something wrong with your oven? I had trouble with my oven once and it was cooking cakes perfectly on top, but they'd be raw in the bottom - it turned out the concealed heating element in the bottom of my oven wasn't working.