Homemade Electromagnet from Microwave oven transformer
a) not safe to plug into mains

b) need more copper wire, fill the available space with turns

c) decide how long you want it to remain attracting for, then aim to heat up your windings in that time, ie use as much input power as you can without overheating. Depending on the cross section of your copper, this may be a car battery, or several in series.

This will allow you to maximise the attraction for that core geometry. It may still not be enough for your spoon.

A steel spoon will be strongly attracted to a magnet. A stainless steel spoon, depending on the precise grade, will be somewhere between very weakly attracted to completely not attracted at all. Make sure you are using the right type of spoon!