If you're doing any holiday baking, you may have found that baking powder can have an annoying habit of not being in the cupboard when you need it. Or maybe it's been there for a couple of years and it's lost its mojo. Either way, don't try to substitute baking soda (which is also sometimes called "sodium bicarbonate," "bicarb soda" or some such variation) for baking powder. This would be a big mistake.

Baking soda and baking powder are leavening agents that make your muffins, scones or whatever rise. Baking soda is alkaline, so it's activated by combining it with an acid like vinegar — or, more commonly in baking, buttermilk.

Baking powder is similar, but it has its acid, in the form of cream of tartar, built in. Which is why using baking soda instead will cause your recipe to turn out wrong — baking soda by itself is missing this crucial acid component. But as long as you have baking soda and cream of tartar, you can make your own baking powder in about thirty seconds.

Crème brûlée is a simple baked custard topped with a crunchy glaze of burnt sugar. Combining decadent richness with an ethereal lightness, this classic dessert embodies all that is good about eggs, cream and sugar.

Crème brûlée sounds like a big deal. But the truth is, if you can bake cookies, you can make crème brûlée. Forget about all those funny accents and things over the letters. It's a custard. Eggs. Cream. Sugar. Keep it simple.

And a good crème brûlée is simple — velvety smooth, not too eggy and not too sweet. This tutorial on how to make crème brûlée will show you how it's done, one step at a time.

The holiday season gives us a chance to serve fabulous meals to big, festive gatherings, and this slow-roasted pork shoulder is perfect for the occasion. It's juicy, crispy and insanely flavorful. And best of all, it's easy to prepare.

Here's what happens: First, we smear the roast with a spice rub made from dried chilis, brown sugar, Kosher salt and a few other ingredients. Then we roast it — first at a very high temperature to brown the outside, and then finish it at a very low temperature, to maximize juiciness.

Check out this amazing slow-roasted pork shoulder recipe. It's beautiful served with a creamy polenta and your favorite veggie.

Making your own mayonnaise is one of the most basic culinary arts skills, and if you haven't done it before, it's a real rite of passage — the culinary equivalent of a baby taking its first steps.

And if you've got the sort of mind that learns best by seeing things demonstrated as opposed to reading about them, the foodies at About.com have put together this short video that shows you how to make mayonnaise.

But first, a word or two about eggs and oil. The guy in the video calls for four egg yolks and a single cup of oil. Note, however, that a single egg yolk can actually hold a cup of oil by itself — though there are risks involved: a single-egg mayonnaise is not very stable. Two egg yolks, though, should be plenty for a single cup of oil. Maybe it's just me, but I think four egg yolks will produce a mayonnaise that's a bit too on the eggy side.

It's just a matter of taste, though, and everything else about the clip is pretty sound. So check out this video on how to make mayonnaise.