1. In a bowl, add oats, coconut, sugar, flour, soda, salt and mix. Add melted butter and mix.
2. Separately, prepare the batter with packaged brownie mix.
3. Into a greased 13x9x2-inch baking pan, pour 3/4th of the oat mixture and pat it to bottom.
4. In a preheated oven, bake the oat mixture at 225 degrees centigrade for about 10 minutes. Allow to cool for about 5 minutes.
5. Now over the cooked crust of the oat mixture, pour the brownie mix, and to with the remaining oat mixture.
6. Bake the entire mix for another 30 minutes.
7. While still warm, cut the brownies into even sized squares.