Caramelized Vidalia Onion Tart

1 stick butter
2 large Vidalia onions, halved and thinly sliced
Salt, black pepper
1 t. dried thyme
1 c. flour
4 t. baking powder
2 t. sugar
2/3 c. milk

1. Melt 2 T. butter in large, heavy skillet over low heat.
2. Season onions with salt, pepper and thyme.
3. Add onions to skillet and cook until tender and lightly browned, 20-30 minutes.
4. Set aside to cool.
5. Place one rack in upper third of oven and another rack in lower third, in preheated 400 oven.
6. Spray two baking sheets with PAM.
7. Mix flour, baking powder, sugar and 1 t. salt in a bowl.
8. Cut remaining butter into small chunks and add to flour mixture.
9. Cut butter using pastry cutter or two knives until mixture resembles coarse meal.
10. Stir in milk with a fork just until flour is evenly moistened.
11. Turn dough onto floured surface and pull together in one piece with floured hands.
12. Divide dough into 48 mounds (about ½ T. each).
13. Roll each into a ball and place on baking sheet.
14. With a teaspoon measuring spoon, press an indentation into center of each ball.
15. Spoon onion mixture into the indentations.
16. Bake, rotating pans halfway through, until golden, 12-15 minutes. Serve warm.