Preheat the oven to 350°F and grease a 9×13 inch pan.

Peach Filling:

1. In a large bowl, stir the peach chunks, brown sugar, cornstarch, lemon juice, vanilla, cinnamon, nutmeg, and salt together until combined and sugar begins to dissolve. Pour filling into prepared baking dish.

Biscuit topping:

1. Whisk the flour, sugar, baking powder, baking soda, and salt together in a large bowl. Add the butter. Using a pastry cutter, forks, or your hands, cut the butter into the mixture until it resembles coarse meal. (if you have a pastry cutter use it and this step will be quick and easy.)
2. Slowly pour in the buttermilk. The dough should be a bit tacky, you may need to add a drizzle more of buttermilk if the dough doesn’t stick together.
3. Using your hands, place dough all over the top of the peach filling. Spread it out as much as possible but don’t worry if peaches are showing through.
4. Brush the top of the biscuit dough with egg wash, then sprinkle with the cinnamon-sugar mixture.
5. Bake 40-45 minutes, or until lightly browned and biscuit topping is cooked through. Set the pan on a wire rack, and cool at least 5 minutes before serving. Serve warm and add vanilla ice cream or whipped cream for an extra special dessert!