Preheat the oven to 400˚F.
To make the peach filling, put peach slices in a 10-inch cast iron skillet or 2.5 qt baking pan. Add the sugars, spices, cornstarch, and salt; toss well and set aside.
To make the biscuit topping, whisk together flour, 1/4 cup sugar, baking powder, and salt in a mixing bowl. Cut in the butter pieces until the flour turns into coarse crumb. Whisk egg and milk together in a small mixing bowl and add to the flour mixture. Using a fork, stir the mixture until just combined.
Using a spoon, drop mounds of biscuit topping on the peach filling. Sprinkle the remaining 2 tablespoon of sugar on top of biscuit topping. Bake the cobbler in the preheated oven for 30-40 minutes until the biscuit top is golden brown. Serve warm with vanilla ice cream.