Preheat the oven to 325 F. Thoroughly grease and flour a 6 cake bundtlette pan. Set aside.
Beat in the egg and vanilla. Scrape the bowl.
Bake for 25 mins, until a cake tester inserted into one of the cakes comes out only smeared candy, no batter. The cakes will also begin to pull away from the sides of the pan, looking like this: