Preheat your oven to 375.
Peel your peaches. Use a paring knife to slice then into thin slices, then remove the slices from the peach pit.
Place the peach slices in a large bowl, and toss them with the 6 tablespoons of sugar, and one teaspoon of cinnamon. Set the bowl aside for later.
Dump the melted butter into a 9x13 cake pan.
In a large bowl, combine the sugar, flour, salt, and baking powder until the dry ingredients are combined.
Add the milk and vanilla, and mix with a fork or a whisk until the batter is relatively smooth (there will be some lumps)
Pour the batter into the 9x13 pan (you don't need to mix it into the butter). Dump the peaches over the top of the batter.
Bake at 375°F for 45 minutes.
The top will be golden brown, and the edges of the cake will begin to pull away from the pan. The middle will still seem jiggly.
Serve warm with vanilla ice cream.