Preheat the oven to 200 degrees F. Pat the cube steak thoroughly dry with paper towels. Then gently stretch the steaks to make them thinner, or better yet, using a meat tenderizing hammer to pound the steaks extra thin. Be sure not to pull or pound so hard that they break. Try to reach 1/4 inch consistency throughout each steak.
In a medium bowl mix the flour, Cajun seasoning, and baking powder together. In another bowl, whisk together 1 1/4 cup milk, eggs, and Worcestershire sauce.
Dip the steaks in the flour mixture. Shake them off, then dunk the steaks in the egg mixture. Shake off the drippings, then dunk back in the flour mixture. Shake off all excess flour. (Flour that falls off into the oil will burn and turn the oil dark.) Allow them to rest on a cutting board while the oil heats.
Place a large skillet over medium-high heat. Add enough oil to fill the skillet 1/4 inch deep. Once the oil in the pan is between 350-375 degrees F, gently place half the steaks in the hot oil and fry for 1-2 minutes per side. Use tongs to move the steaks to a paper towel-lined plate. Add additional oil to the skillet if needed, and repeat with the remaining steaks. Place the finished steaks in the oven to keep warm.
Once all the steaks are fried, carefully pour the oil into a tin can for disposal. Then wipe the skillet out with a paper towel. Place it back over medium heat and add the butter. Once melted, whisk in 1/3 cup of the remaining seasoned flour. Whisk until bubbling, then whisk in 2 3/4 cups of milk. Continue to whisk the gravy until it is thick. Taste, then season with salt and pepper as needed. Remove the gravy from heat. If the gravy starts to thicken too much, whisk in an additional 1/2 cup of milk.
Serve the steaks warm with gravy over the top.
The thinner the cube steaks are, the better. Stretch them gently. Yet if they are not tenderized enough to stretch, you can pound them with a meat tenderizer. The goal is to make them no more than 1/4 inch thick.