Is pure vanilla that has expired six months ago still safe to use in my baking?

it should be fine, if a little lesss flavorful than a younger batch

have you considered making your own?

Ingredients;
2 Cups (16 oz.) vodka
You may also use Brandy or Rum.
(rum will give it a sweet flavor)
6 Vanilla Beans

You can easily cut this recipe in half and use 3 vanilla beans and 1 cup of vodka, brandy or rum.

You can use any kind of bottle you want, but I do recommend glass.

Cut the vanilla beans the long way with a scissors except the last inch. This way the bean stays intact.

Pour the vodka into the container you will be making your extract in. Here you see a quart mason jar.

I like to use clear glass, so I can see how the extract is developing. The darker it gets the stronger the extract is. There is no exact time that the extract is done. I like to wait at least 8 weeks.

Put the cut beans in the vodka and push them down until they are completely covered. They usually won’t go down completely on their own as you see in this picture, so they need to be pushed down even farther.

Cover the vanilla extract and let it sit in a cupboard out of the light. You will start to taste some vanilla flavor even after a few days. How long you let it sit is how potent your vanilla extract is.

After 8 weeks the vanilla extract has the nice amber color and I am pouring it into small bottles for gifts.

I like to put a vanilla bean in each bottle. This way the extract will keep gaining in flavor and you can tell them that by adding a little vodka when it is halfway used up will replenish your supply of vanilla. It will dilute it for a while but it will regain strength quickly.

Some people will add some simple sugar syrup to the extract to sweeten it. . This is what they do in most commercial varieties so it has a nice sweet aftertaste.
I like to use a little dark rum in my extract instead.

(1 teaspoon per cup of vodka)

Here I have made a label for the extract using an avery label.

it should be just try it and if it does not taste good then dont use it in your cooking

It should be OK, just smell it first, and then try it. Expiration dates can be flexible according to the product.