Whisk together the flour and salt in a large bowl. In a separate bowl beat together the eggs, milk and butter. Make a well in the flour and whisk in the wet ingredients gradually until fully combined and smooth. Whisk in the poppy seeds and orange zest. Cover the bowl with plastic wrap and allow the batter to rest for 1 hour at room temperature.
Preheat the oven to 400 degrees F.
Peel and section the orange. Reserve pieces of orange - make sure there are no seeds. Grease a large muffin tin. Place the tin in the oven to heat up for at least 10 minutes. Once heated place one piece of orange on the bottom of each cup. Give the batter a quick stir and pour into each cup filling them halfway leaving room for them to rise.
Place in the oven and do not open for 30 minutes. They should rise after 30 minutes and be golden all over. Remove from oven. You can check to see if it's ready by cutting into one - the inside should be mostly hollow. Serve immediately with Vanilla Butter.
In a small bowl mix the softened butter, sugar and vanilla seeds (discard the bean) until well incorporated. Spread on warm Orange Poppy Seed Yorkshire Pudding or save for another use.;
Other serving suggestions: marmalade, whipped cream, and jam.