To Make the Topping: Add both sugars and the vegetable oil to a medium bowl and mix well until combined. Whisk in the egg until the mix is smooth and starting to look frothy. This will take 1-2 minutes, depending on your arm strength. Sprinkle the remaining topping ingredients over the egg mix. Stir everything together very well, until a soft cookie dough forms. Cover and refrigerate while you prepare the fruit. Make the Fruit Filling: Preheat the oven to 350°F. While the topping is chilling, pit and slice the peaches. If you prefer to peel them, go ahead. But it's not necessary and I'm usually too lazy to do so. Place the peach slices and blueberries in a lightly greased 8x8 inch square baking pan. Sprinkle the flour, sugar and cinnamon over the fruit and carefully toss. Scatter the topping evenly over the fruit filling in large blobs, making sure to cover all the fruit. Bake the cobbler on the middle rack of the preheated oven for 25-30 minutes or until a toothpick inserted into the topping comes out clean and the filling is bubbling up around the sides.