Preheat the oven to 350 degrees F. Spray 8x8" baking dish with non-stick spray. (I used a round 1.5 quart dish, but you can also use a square 9x9 baking dish).
Pour sliced peaches from cans in the bottom of your pan (drain only 1 can of liquid). In a separate bowl, whisk together cake mix and cinnamon. In a small bowl, stir together melted butter and vanilla extract.
Top the peaches with cake mix mixture, then drizzle with the melted butter mixture. Bake for approximately 35-40 minutes, or until the top becomes slightly golden brown.
Remove from the oven and cool slightly before serving.Top with ice cream, if desired.