Step 1

Preheat oven to 375 degrees F (190 degrees C). Place a baking sheet on the rack under the middle rack to catch drips. Generously butter a 2-inch deep (2-quart) baking dish.

Step 2

Place peach sections into prepared baking dish. Sprinkle with lemon juice and zest.

Step 3

Stir butter and sugar together in a mixing bowl. Mix until creamed and resembles a sugary, buttery paste, 4 to 5 minutes. Add oats and flour; stir until flour and oats are incorporated into the butter-sugar mixture and mixture resembles coarse crumbs, 4 to 5 minutes. Pour in milk; stir until mixture is wet and creamy, like a thick spreadable batter, 3 to 4 minutes.

Step 4

Drop batter by spoonful on top of the peaches. Spread batter evenly over the surface of the peaches. Sprinkle 1/4 cup sugar on the batter. Spritz with water until sugar is wet and surface glistens.

Step 5

Bake in preheated oven on middle rack until browned and crispy, about 45 minutes. Let cool at least 30 minutes before serving.