Preheat your oven to 350°F (177°C). Grease a 9x13-inch baking dish with butter and melt ½ cup of unsalted butter in it as the oven heats.

In a large mixing bowl, combine 1 cup of all-purpose flour, ½ cup of granulated sugar, 1 tablespoon of baking powder, and a pinch of salt. Stir until mixed, then mix in 1 cup of whole milk until just combined.

Pour the batter over the melted butter in the baking dish without stirring, ensuring an even layer.

Toss 4 cups of sliced peaches with ¼ cup of sugar and 1 teaspoon of cinnamon. Let sit for a few minutes.

Spoon the peach mixture over the batter in the baking dish, ensuring not to stir.

Bake for 45–50 minutes until golden brown and bubbly.

Remove from oven and let cool for 10-15 minutes before serving.