Preheat the oven to 350°F and line an 8x8 baking pan with parchment paper (or coat with nonstick spray).

Halve peaches and remove pit, then slice or cut into chunks (peeling isn’t necessary).

Toss in a bowl with 1 tablespoon brown sugar and set aside.

In a large bowl, combine flour, granulated sugar, baking powder, salt, and cinnamon.

Whisk together egg and milk, then pour into dry mixture and stir until well combined.

Add peaches, leaving excess liquid behind, and fold to combine into batter. Pour into prepared pan.

To make the topping, in a small bowl, combine flour, brown sugar, granulated sugar, and salt. Cut in butter with a pastry blender or two knives until mixture forms small chunks and looks a bit like clumpy wet sand. Scatter over the top of the batter in the pan.

Bake for 30-40 minutes, until browned and a toothpick inserted in the center comes out clean.