I just finished eating my frozen yogurt from earlier, and it was delicious. I must warn you, though, that frozen yogurt is not the same as ice cream, and it doesn't taste like ice cream. Yogurt will always have that sour yogurt taste. However, if you're in the mood for it, it's just perfect. And, of course, much better for you.
Frozen Yogurt for One
1 cup plain yogurt
2 tablespoons brown sugar
1/2 teaspoon vanilla
Put all ingredients in a mug and stir until completely blended. Put in the back of the freezer for about three hours. Then take out, stir, and enjoy!
I stirred every hour or two, but it really doesn't seem to have made a difference. If you leave it in longer, though, it might get too hard if you don't stir before serving.
That is kind of a lot of sugar I put in. The thing is, frozen things need more sugar to still taste sweet. You could cut the sugar a tad, but it will be more sour that way. You can taste as you mix the ingredients together -- it will taste about the same frozen, just keep in mind that the flavors will not be quite as strong.
Straciatella: Omit vanilla and add mini chocolate chips.
Fruit: Omit vanilla, reduce sugar a bit, and add fruit preserves, puree, or whole fruit pieces. You could also just freeze fruit yogurt.
Spice: Omit vanilla and add a sprinkle each of cinnamon and nutmeg. You could also replace some of the sugar with molasses and add a bit of ginger. Or maybe some cooked apples!
Chocolate: I considered blending in chocolate syrup. I'm not sure how that would blend with the sour yogurt taste. I decided against it, but you could still give it a try.