When preparing Yorkshire Pudding, make sure you use fat rendered from your roast to grease the pan. That takes a little forethought to not trim fat from the roast, in fact it requires selecting a roast that has a thick fat cap. I typically use a muffin tin and fill each hole one quarter full of rendered fat. Additionally, don’t make the batter at the last minute. Immediately following putting the roast in the oven, prepare the batter. The flour needs to be well hydrated which cannot be accomplished at the last minute. That’s similar to making good crepes.
When I grew up, the pudding was put in a pan below the roast which was on a rack, not a pan, so that the drippings fell throughout. Oh my!