kitchen failure

There's a thin and extremely sticky gummified brown coat of oil cooked onto the bottom of the oven, and it almost completely covers the surface. It won't come off with scrubbing, except for in a thin layer of brown grime on a scrub brush, but it will start burning up as soon as the oven heats up. So I guess I need some oven cleaner. And no, this has never happened to me before! If you know of the common household product that will remove this grime, please, tell me.

In related news, I accidentally used too little butter in the cookies I was making and the batter was dry. So, in my flustered state, along with the rapeseed oil I was gradually drizzling in I drizzled in some boiling water to make it easier to stir... but, uh, I forgot about the chocolate chips. Which all melted. So. We'll see how that turns out tomorrow. After I'm actually able to turn the oven on again.