3 cups quick-cooking oats
1/2 cup all-purpose flour
2 teaspoons baking powder
2 teaspoons ground cinnamon
1/2 cup butter, melted and cooled to room temperature
1/2 cup vegetable oil
1 cup light brown sugar, firmly packed
1/4 cup granulated sugar
2 large eggs, lightly beaten
Preheat oven to 350°F (175°C). Lightly grease a 13 x 9 x 2-inch baking pan with cooking spray; set aside.
Combine oats, flour, baking powder and cinnamon in a medium bowl and mix well; set aside.
In another bowl, combine the melted butter, oil, both sugars and the eggs, mixing well with a wooden spoon. Stir in the oat mixture until just combined. Spread dough evenly into prepared pan.
Bake for 15 minutes; reduce oven temperature to 300°F (150°C) and bake for another 15 to 20 minutes or until wooden pick inserted in the center comes out clean.
Cool in the pan on a wire rack before cutting into squares.