Preheat the Oven: Preheat your oven to 350°F and grease a 13x9-inch baking dish with butter or non-stick spray.
Prepare the Peaches: Pour 1 can of peaches (with the syrup) into the prepared baking dish. Drain the second can of peaches and add just the peach slices to the dish.
Add Sweetness and Spice: Sprinkle the peaches evenly with 2 tablespoons of brown sugar and 1 teaspoon of ground cinnamon.
Layer the Cake Mix: Sprinkle the yellow cake mix evenly over the peach mixture. Make sure the entire top is covered, but do not mix the layers.
Add Crunch and Butter: Sprinkle 3/4 cup of sliced almonds over the cake mix. Arrange the slices of cold butter evenly on top of the cake mix, spacing them to cover most of the surface.
Bake: Place the dish in the preheated oven and bake for 35-40 minutes, or until the top is golden brown and the peaches are bubbling around the edges.
Serve: Allow the cake to cool for a few minutes before serving. Serve warm with vanilla ice cream or whipped cream for the ultimate dessert experience.