I did something similar just recently! but this one turns into a nice cookie like thing
2 cups oats
1-2 bananas mashed
several packets of saccharin or splenda
1 tsp of baking powder
1 cup almond milk (much better than regular milk, no sugar, low calories)
shredded coconut (ON top)
mix it all up cept coconut, put into a big baking dish then spread the coconut on top, the dish should be big enough so that the batter is < 1 inch thick. Also, Coconut is fatty and sugary so be sparing here, a little goes a long way as far as taste anyway. then bake 375 for 35 minutes.
The top will crisp, the coconut will too, and it will taste absolutely decadent. The only sugar is from the banana and the coconut and both can be adjusted.
this is kind of like a "solid" version of what you are talking about.