When I first started baking, I was on the quest to find the PERFECT cake or cupcake recipe. I honestly spent hours searching the internet, testing different recipes, and tweaking the ones I found to make them my own. What I realized that the best recipes have a little something different or extra included in the ingredient list. Now you won't find these ingredients in your typical cake recipe, but they are definitely worth buying.
I use King Arthur's Espresso powder in my chocolate cakes and brownies. It adds a little complexity to the chocolate taste without over-powering it, just like vanilla. You can dissolve the powder in hot water or heavy cream if you want to add it to your buttercream, that way it won't leave any specks. Or you can add the powder to your dry ingredients. You can also use to to create a mocha flavored dessert. All you have to do is add about two tablespoons worth of powder to your dessert or frosting.
Cream of Tartar
If you don't have baking powder, cream of tartar reacts with baking soda to help the cake rise. However, I wouldn't really suggest making your own. Also, it's added to egg whites to help stabilize them and increase the volume. I use cream of tartar whenever I make marshmallow fluff and in some of my cake recipes.
The secret to stabilized whipped cream is gelatine. Incorporating it into heavy cream can be tricky, but you won't have to worry about your whipped cream be a drippy mess when you serve the dessert. It's also used in making cheesecakes, jello, and mousse.
Stay sweet! Randi