Using a yogurt cheese maker or layered cheese cloth, strain the whey from 1 quart of yogurt for 3-6 hours in the refrigerator. This should yield 1 cup of yogurt cheese.
Preheat oven to 375°.
Cream together brown sugar and butter until fluffy.
Add yogurt, vanilla, and eggs.
Fold in pineapple.
In separate bowl mix together flour, oats, baking powder, cinnamon, and salt.
Fold into wet ingredients.
Form into 1 1/2 inch balls.
Place on greased baking sheet 2 inches apart.
Bake until golden, about 12 minutes.
Transfer to cooling racks.