2 tbsp butter, at room temperature
2 tbsp vegetable oil
1 cup firmly packed dark brown sugar
1 large egg
1/2 cup unsweetened applesauce
1 tsp vanilla
1 1/2 cups all-purpose flour
1 tsp baking powder
1/2 tsp baking soda
1/2 tsp salt
2 cups regular rolled oats
1 cup semisweet chocolate chips
2 tbsp granulated sugar
1. In a large bowl, with an electric mixer on medium speed, beat butter, oil, and brown sugar until smooth. Beat in egg, applesauce, and vanilla until well blended.
2. In another bowl, mix flour, baking powder, baking soda, and salt; stir or beat into butter mixture until smooth, scraping down sides of bowl as needed. Stir in oats and chocolate chips.
3. Spread dough evenly in a lightly oiled 8-inch square baking pan. Sprinkle top evenly with granulated sugar.
4. Bake in a 350° oven until pale golden brown, about 15 minutes. Let cool on a rack about 10 minutes, then cut into bars.