Preheat oven to 350 degrees. Toss peaches with brown sugar and vanilla in a medium sized bowl and let them stand for 10-15 minutes. When the peaches are syrupy pour them into a 9 x 13 dish.
In another bowl mix cake mix with pecans and cinnamon and crumble with your fingers or a fork. Sprinkle over the peach mixture. Pour the melted butter over the top. Bake in the preheated oven for 45 min. If the edges are getting too brown but the middle isn't done put foil around the edges and bake about another 10-15 minutes.
Serve warm with vanilla ice cream,if desired. Other fruit can be substituted. This would be something quick and easy to put in the oven while you are eating dinner and then serve it warm for dessert.