First you need a pie crust mold. The crust will be a two-part crust, with each part being baked around semi-spherical object. You might have something around the house that's got a fantastic semi-circular shape but it should be made from an oven-worthy material. I am using a glass candle holder that has been cleaned thoroughly and has no wax residue. Since it is not tempered, it's important to be very careful and not to allow the glass to cool too quickly. So do not put it in the refrigerator, in your sub-zero detached garage, etc. to cool it faster. Just wait. If you choose glass, be careful! Do this at your own risk. (People will have issues with my use of non-tempered glass so this is for their satisfaction.)
Calculate the volume of filling. Measure around the widest part of the sphere. This is the circumference. If you don't have a flexible measuring tape, wrap a piece of string around it, mark it, and measure that. Use this to calculate the volume of your sphere. This sphere calculator
will calculate the volume for you. A cup of pudding is approximately 14.5 square inches. My 11" diameter mold will result in 22.45 square inches, about 1 1/2 cups filling so I made two cups of filling.
I had an amazing semi-circular candle shade that was almost a perfect sphere with little holes for light and oxygen to go through. However, I calculated the volume of this 22" diameter sphere and it was a staggering 180 cubic inches requiring about 12 cups filling. This is why I went with a smaller mold.