Preheat your oven to 350°F (175°C) and grease a 9x13 inch baking dish.

Peel, core, and slice 4-5 medium tart apples into thin wedges. In a bowl, combine with ground cinnamon and brown sugar.

Spread the apple mixture evenly across the bottom of the greased baking dish.

Sprinkle the dry yellow cake mix evenly over the apple layer without mixing.

Melt the stick of unsalted butter and drizzle it over the cake mix layer.

Bake for 45-50 minutes or until golden brown and bubbling around the edges.

Let the cake cool for 10-15 minutes before serving, best enjoyed warm with ice cream or whipped cream.