Carry a small spice jar of cinnamon or cocoa powder in your glove box, it totally changes a basic cup. I even keep those single serve powdered creamers from diners, the French vanilla kind. Pour your instant in first, then the hot water, and stir in a pinch of whatever. Turns a survival coffee into something you actually want to drink. Makes those long drives way more bearable when you have a good cup.
Wait you keep those little creamers in your glove box too? I mean idk maybe it's just me but that sounds like a melted mess waiting to happen. Like @sage_jackson56 said about the cumin, anything powdery is gonna leak or explode in the heat. My car gets so hot in the summer, I can't imagine opening my glove box to find French vanilla goo all over my registration. The spice jar idea is cool in theory but I'd be too paranoid.