Preheat oven to 425°F. Place a large baking sheet covered in foil on the lowest rack. This will catch drips as the cobbler tends to overflow.

In a large bowl, combine the sliced peaches and lemon juice. Add sugar, cinnamon, nutmeg, and cornstarch. Stir to coat the peaches evenly and transfer to a baking dish.

Bake the peaches for 10 minutes. Meanwhile, in a bowl, whisk together flour, white sugar, brown sugar, baking powder, and salt. Add the grated butter and mix until crumbly. Stir in boiling water just until combined.

Remove the peaches from the oven and drop spoonfuls of the topping mixture over the peaches. Bake until the crust is golden, about 28 minutes.

Serve warm or at room temperature. Enjoy your homemade peach cobbler!