Preheat your oven to 350°F (175°C). Yes, it’s fine to pretend you’re a professional chef for a hot minute.
Wash and slice the peaches if you’re using fresh. Toss them with white sugar, brown sugar, cinnamon, and lemon juice. Let them mingle while you do the next step.
In a separate bowl, whisk together flour, baking powder, and salt. Pour in milk and melted butter; stir until just combined. Don’t overmix—the batter should be a little rustic, not smooth as a baby’s bottom.
Pour the batter into a greased baking dish. Spoon the peach mixture on top; the juice will seep down, which is exactly what you want.
Bake for about 40-45 minutes, until the edges are golden and the top is bubbling. If the top browns too fast, cover with foil for the last 10 minutes.
Let it cool for a few minutes, scoop generously, and serve with ice cream or whipped cream if you’re feeling fancy.