Preheat the oven to 350℉/170℃. For easy removal of the bars, place parchment paper on the bottom and 2 sides of the pan. Gently grease the other two sides and then set aside.
In a medium sized bowl, add in flour, cinnamon, rolled oats, cornstarch, baking powder, baking soda, coconut, and salt. Stir to combine and set aside.
1 1/2 cups rolled oats, 1 3/4 cups all-purpose flour, 1/2 tsp baking soda, 3/4 tsp baking powder, 1/4 tsp cinnamon, 1 tbsp cornstarch, 1/4 tsp salt, 1 cup shredded coconut
In a large bowl, add melted and slightly cooled butter, oil, and brown sugar. Mix for 2-3 minutes until well combined. Make sure to scrap the sides of the bowl.
3/4 cups butter, 1 cup light brown sugar, 3 tbsp flavourless oil
Whisk in the eggs for another 2-3 minutes, until the mixture is paler in colour and air bubbles are forming.
2 eggs
Mix in the maple syrup and vanilla until just combined.
1 tbsp vanilla, 3 tbsp maple syrup
Add the dry into the wet and using a spatula, mix until just combined and no flour streaks appear. Do not over-mix!
Add in the mini chocolate chips and mix until just combined. Do not over-mix!
1/2 cup mini chocolate chips
Transfer the dough into the prepared pan and spread evenly. Add extra chocolate chips on top (optional).
Bake the bars for 25-35 minutes. Mine took 32 minutes exactly. The bars are ready when the edges will be a golden brown colour, and a toothpick inserted will come out clean.