Preheat the oven to 350 and prepare a donut pan with grease. Set to the side.
Make the crumb topping. In a medium-sized bowl, combine the brown sugar, granulated sugar, cinnamon, flour, and melted butter. Mix with a fork until crumbs start to form. Set to the side.
Slice the peaches. Roughly chop them into small chunks. The pieces do not need to be uniform.
Make the donut batter. In a large bowl, mix the flour, baking powder, baking soda, salt, cinnamon, nutmeg, and salt. Then, add the eggs, melted butter, brown sugar, milk, sour cream, and vanilla. Use a whisk to mix everything together.
Form the donuts. Fill the donut pan about ⅔rds of the way full. Then top with peaches, followed by the crumb topping. If the peaches and crumbs are falling out, press them down into the batter to stick.
Bake the donuts for 10 to 12 minutes. Let them fully cool before removing them from the pan.
