Toss together the sliced peaches, 1/3 cup sugar, 2 tablespoons flour and 1 teaspoon ground cinnamon. Pour in the bottom of a lightly greased 9x13" pan.
In a separate bowl, whisk together the flour, sugar, baking powder and salt. Add in the oil and milk and whisk to just combine, taking care not to over mix.
Spread the mixture over the peaches and place in the oven. Bake for 30-35 minutes until golden browned and bubbly. Remove, let cool slightly and enjoy. We love this best with vanilla ice cream on top!