Preheat the oven to 400 degrees.

Starting at the outer edge, cut most of the way through each apple half at 1/8 inch intervals.

Place apple halves, cut side down, in an 8 x 8 baking dish coated with cooking spray.

Combine 1 T. brown sugar, 1 T. butter, and 1/2 t. cinnamon. Brush the mixture over top of the apples.

Cover the pan with foil and bake for 15 minutes. Remove the foil and bake for 10 minutes.

Remove from oven and allow to cool 10 minutes.

Combine the remaining brown sugar, butter, and cinnamon along with the oats, flour, and salt. Carefully open up the cuts in the apples and fill with the sugar and oat mixture.

Bake at 400 degrees for 10 minutes. Turn on the broiler and broil for 2 minutes. Serve immediately.