Preheat oven to 425 degrees F.
Peel and slice peaches and soak them in bourbon for an 1-2 hours.
Strain off bourbon (save it for your drink later!).
Mix peaches with brown and white sugar, corn starch, nutmeg, and cinnamon in a large bowl.
Transfer peach mixture to glass baking pan and bake for 10 minutes and remove from oven.
Mix together flour, white and brown sugar, baking powder, and salt. Add butter and mix together until you get a mealy texture. Stir in boiling water until just combined. Scoop tablespoon sized dollops of mascarpone cheese into the peach mixture. Sprinkle topping on peach mixture and top with extra cinnamon.
Bake for 30 minutes, until top is golden brown.