Combine the first 4 ingredients in your mixer (flour, baking powder, salt and veg oil) and let 'er rip. It'll be super dry and crumbly, but that's cool. You just want everything to be well incorporated. Next, add the warm "milk" (I just microwaved mine for 45 seconds) slowly, 1/4 cup at a time until you end up with a smooth and well-mixed sticky mess.
On a well-floured surface, knead the dough for a full 5 minutes until it's not a big sticky mess. I was lazy, so I just dumped a couple handfuls of flour in my KitchenAid mixer and revved that for 5 minutes until the dough wasn't sticking to everything anymore.
After you have a smooth and not quite as sticky dough, place it in a bowl and cover with a damp cloth for 20 minutes. This step is important so that your dough can rest a wee bit and become more manageable.
After the 20 minutes, cut/rip the dough into 8 equal pieces, roll them into little balls and place them on a plate (make sure they're not touching!) covered with the damp cloth for another 10 minutes.
On a floured surface, pat your balls (lolz) into little circles about 4 inches in diameter.
Take a rolling pin and roll out the circles into 8 inch rounds, starting from the middle and moving out.
Heat up a pan and keep it dry - this means no oil or anything of the like.
Once your tortillas are sufficiently flat (this was the hard part for me) place them one at a time in the pan for about 30 seconds per side, or less, depending on how hot your pan is. They'll get little (or big) bubbles when they're done.
Keep the cooked ones warm in a cloth towel until you're ready to eat them or alternatively, if you don't want to eat them all at once, you can store 'em in foil or something in the refrigerator for a few days.
Try re-heating them up in the oven wrapped in foil for best effect before serving.