Preheat oven to 350°F.

In a medium mixing bowl whisk together your melted butter and brown sugar. Spread the mixture on the bottom of the high-sided 9-inch cake pan.

Place the peach slices evenly over the top of the brown sugar mixture in the pan and set aside.

In a large mixing bowl, whisk together the flour, baking powder, salt, and cinnamon. Set aside.

In another mixing bowl, beat together the butter and both sugars until light and fluffy. 

Add egg and vanilla, then beat until combined.

Add in the flour mixture and beat until combined.

Finally, add in the milk until well combined.

Spoon the cake batter over the peaches and gently spread it over the top.

Bake for 35-40 minutes until golden brown and toothpick inserted near the center tests clean.

Remove the pan from the oven and let cool in the pan for 5-10 minutes before flipping out onto a serving tray.

Cut and serve warm or cool.

To serve, top with ice cream if desired.