Well I always sieve my flour to get some air into it my milk goes in a bit at a time from a height to create more bubbles I like my oil hotter than that I wasn't even sizzling when you put the battery in so why wasn't the tray with oil in put in the oven while the prepping was done about 15 minutes to get it really hot and I only used 2 eggs to a 100m of flour 100m of milk I noticed you never seasoned the flour
Four eggs is two too many and reduce milk by half and replace with equal amount of water……you will then get proper batter pudding and not unsweetened cake.