1Preheat oven to 350 degrees F (175 degrees C). Butter a 9x9 inch baking pan.
2In a medium bowl, combine flour and 2 tablespoons brown sugar. Cut in butter until mixture is crumbly. Press into the bottom of the prepared pan.
3Bake for 15 minutes in preheated oven. Crust should not be fully cooked.
4In a large bowl, mix together the eggs and remaining brown sugar. Combine the oats, salt, and baking powder; stir into the egg mixture along with the vanilla. Mix in raisins and coconut, if desired. Spread the mixture evenly over the partially baked crumb layer in pan.
5Bake 20 minutes more. Cool, and cut into squares.
Footnotes
Tip
Aluminum foil can be used to keep food moist, cook it evenly, and make clean-up easier.