This probably isn't a seasonal suggestion, but frozen hot chocolate is one of my favorite summertime treats and a good way to use that hot cocoa mix all year round!

You could re-gift it (to friends or the other side of the family so she won't know or get hurt...) - pour some in a jar and tie a pretty ribbon around the top of it with a nice little nametag and instructions how to make cocoa.

I usually bring things like that into the office. It's gone by the next time I walk into the lunchroom.

I use mine as part of my base for chocolate ice cream or pudding. Doctor it up with vanilla and real chocolate, some cinnamon, etc..

You can make it into a frosting: http://www.verybestbaking.com/recipes/detail.aspx?ID=107661
I've been meaning to try it but never have.
Also, I guess it goes without saying, this recipe is for the kind of cocoa mix with sugar added.

You could probably add it to cake mix for a little chocolate flavor added, or marbleizing.

i pour it (dry) on top of ice cream, Fro-Yo or plain non-fat super thick greek yogurt for a yummy snack.

I always put it on plain oatmeal :)

Instant cakes!

http://www.ehow.com/how_5055922_make-using-hot-cocoa-mix.html

The younger set at our family Christmas dinner, are served peppermint hot chocolate and homemade marshmallows.
I then send home the extra chocolate mix and some marshmallows in a dessert basket for each family. I usually bake a dozen types of biscotti, cookies, holiday mini-cakes and the family fudge. Keeping alive the family tradition of having homemade goodies at each house that remind us of our Mom's yearly open house parties and using her recipes.

Make Swedish Sour Cream Cake:

2-3/4 cups flour
1-1/2 cups sugar
1/2 pound unsalted butter
3 eggs
1 cup sour cream
1 tsp baking soda
1 tsp vanilla extract
6 heaping tbsp instant cocoa
1/2 cup semisweet chocolate chips

In a mixing bowl, combine the first 3 ingredients. Take off and reserve 1/2 cup crumbs for top of cake. Add eggs, sour cream, baking soda, and vanilla and mix well. Pour half of the batter into a well-greased tube (Bundt) pan. Sprinkle instant cocoa on top of batter. Mix chocolate chips in rest of batter, and pour that over the bottom half. Sprinkle the reserved crumbs over the top of cake. Bake at 350° 1 hour or until the tester comes out dry.

As a mother-in-law I would prefer to be told you don't want (need) anymore.

Add it to your coffee in the morning!
Makes a great mellow-tasting mocha. And, no need to add milk or sugar!

Blend a frozen banana in a food processor and add hot cocoa mix to taste. Makes a delicious cocoa/banana "ice cream".

Have a brunch party or holiday party, put a pot of hot cocoa on the stove and serve it to guests. Yum!

I often get rid of random things by having parties...making a punch and tossing various little bits of rum in, or I just made trail mix for another party with a bunch of leftovers. Yum!

There's a recipe on my tin of Ghiradelli hot chocolate mix for brownies, where you use less sugar.

But I really like the re-gifting idea! I'm a huge fan of regifting! Both last year and this year I brought a "regift" to a Dirty Santa party, and my gift got fought over! Last year it was martini glasses, and this year it was hand cream and hand scrub. :D

Yeh, for the mother in law who's saying she'd like to be told? You're one in a million and your in law should be happy to be able to deal with you so honestly and directly. It's taken years for my mother in law to actually believe me when I tell her: "No thank you, don't need it (or want it.)" and told very nicely.

So, if you can't say no or it's not accepted, then regift-I love the clear jar idea. Oh, and bringing it to work is a favorite, too.

You can microwave chocolate cake with it.

Possibly a food pantry would put it to good use?

Plan a gourmet hot cocoa party (perhaps for New Years? A winter birthday?)

Do a hot cocoa bar, with white and dark chocolate shavings, mini (or gourmet) marshmallows, and various "spirits" for people to create their own concoctions.

I'm also wondering if the USO might have some use for it?

Take it to your local senior center and let them use it for there functions and lunch programs. Senior centers love hot cocoa mixes, coffee and treats. It will definitely be used and loved.

Your local food shelf. Lots of kids out there who would love a treat like that.

I put a teaspoon or so into plain yogurts or ricotta cheese, add slivered almonds an I have a dessert that doesn't make me feel guilty.

Yes, if it's truly an obscene amount, I agree with the donation suggestions. Senior centers or anywhere that feeds struggling families will find good use for it.

Mixed in with waffle miz and top waffles with whipped cream (and peanut butter in my case)

thanks to one of these suggestions, I'm drinking my cocoa mix with a splash of cognac. and IT'S DELICIOUS. wow. I can't wait to blend some with milk & a banana - that sounds great, too.