Add the peaches, butter, sugars, and cinnamon to a large skillet over medium heat.
Stir until the butter melts and the sugar dissolves, about 2 to 3 minutes. The peaches will soften slightly, and the butter and sugar will make a sauce that coats the peaches.
Remove from heat and allow to cool while you make the whipped cream or to serve cold, chill for 30 minutes.
Meanwhile, using a mixer or food processor, beat the cream and sugar until soft peaks form.
Spoon the peaches and sauce into bowls and serve topped with whipped cream.
Notes
Look for peaches that aren’t too ripe. Very ripe peaches will get too soft as they cook and become mushy.
I made the whipped cream from scratch, but store-bought will workif you’re short on time.